From d4718e0755eac1e505292d0fb7cfd8682eca3048 Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Wed, 22 May 2024 17:08:02 -0400
Subject: [PATCH 1/2] playground: better console (#11719)

* remove unused code

* better console

* simplify

* simplify

* fix

* fix

* fix

* fix console.table

* more table tweaks

* improve table styles

* tweaks

* bump svelte-json-tree

* tweak group styles

* level -> command

* remove stack from assertions

* nicer style for duplicates

* styles

* tidy/simplify

* tweaks

* tweaks

* tweaks

* fixes

* better stack traces (albeit not sourcemapped yet)
---
 pnpm-lock.yaml                                | 170 ++++-----
 sites/svelte-5-preview/package.json           |   2 +-
 .../src/lib/Output/ReplProxy.js               |  63 ++--
 .../src/lib/Output/Viewer.svelte              |  56 +--
 .../src/lib/Output/console/Console.svelte     |  48 ++-
 .../src/lib/Output/console/ConsoleLine.svelte | 219 ++++++------
 .../lib/Output/console/ConsoleTable.svelte    | 117 +++++--
 .../src/lib/Output/console/console.d.ts       |  15 +-
 .../src/lib/Output/proxy.d.ts                 |   8 +-
 .../src/lib/Output/srcdoc/index.html          | 330 ++++++++----------
 10 files changed, 524 insertions(+), 504 deletions(-)

diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3eef183e05..831ab89d1f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -16,7 +16,7 @@ importers:
         version: 2.27.1
       '@sveltejs/eslint-config':
         specifier: ^7.0.1
-        version: 7.0.1(@stylistic/eslint-plugin-js@1.8.0)(eslint-config-prettier@9.1.0)(eslint-plugin-svelte@2.38.0)(eslint-plugin-unicorn@52.0.0)(eslint@9.0.0)(typescript-eslint@7.6.0)(typescript@5.3.3)
+        version: 7.0.1(@stylistic/eslint-plugin-js@2.1.0)(eslint-config-prettier@9.1.0)(eslint-plugin-svelte@2.39.0)(eslint-plugin-unicorn@53.0.0)(eslint@9.0.0)(typescript-eslint@7.6.0)(typescript@5.3.3)
       '@svitejs/changesets-changelog-github-compact':
         specifier: ^1.1.0
         version: 1.1.0
@@ -131,7 +131,7 @@ importers:
         version: 0.19.11
       knip:
         specifier: ^4.2.1
-        version: 4.2.1(@types/node@20.12.7)(typescript@5.4.5)
+        version: 4.2.1(@types/node@20.12.12)(typescript@5.4.5)
       rollup:
         specifier: ^4.9.5
         version: 4.9.5
@@ -221,7 +221,7 @@ importers:
         version: 0.0.15(@codemirror/autocomplete@6.12.0)(@codemirror/commands@6.3.3)(@codemirror/language@6.10.1)(@codemirror/lint@6.5.0)(@codemirror/search@6.5.6)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)
       '@replit/codemirror-lang-svelte':
         specifier: ^6.0.0
-        version: 6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.15)(@lezer/lr@1.4.0)
+        version: 6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.16)(@lezer/lr@1.4.0)
       '@rich_harris/svelte-split-pane':
         specifier: ^1.1.3
         version: 1.1.3(svelte@packages+svelte)
@@ -244,7 +244,7 @@ importers:
         specifier: ^2.0.2
         version: 2.0.2
       svelte-json-tree:
-        specifier: ^2.1.0
+        specifier: ^2.2.0
         version: 2.2.0(svelte@packages+svelte)
       zimmerframe:
         specifier: ^1.1.1
@@ -312,7 +312,7 @@ importers:
         version: 2.39.3
       '@sveltejs/repl':
         specifier: 0.6.0
-        version: 0.6.0(@codemirror/lang-html@6.4.9)(@codemirror/search@6.5.6)(@lezer/common@1.2.1)(@lezer/javascript@1.4.15)(@lezer/lr@1.4.0)(@sveltejs/kit@2.4.3)(svelte@4.2.9)
+        version: 0.6.0(@codemirror/lang-html@6.4.9)(@codemirror/search@6.5.6)(@lezer/common@1.2.1)(@lezer/javascript@1.4.16)(@lezer/lr@1.4.0)(@sveltejs/kit@2.4.3)(svelte@4.2.9)
       cookie:
         specifier: ^0.6.0
         version: 0.6.0
@@ -807,11 +807,11 @@ packages:
     dependencies:
       '@codemirror/autocomplete': 6.16.0(@codemirror/language@6.10.1)(@codemirror/state@6.4.1)(@codemirror/view@6.26.3)(@lezer/common@1.2.1)
       '@codemirror/language': 6.10.1
-      '@codemirror/lint': 6.7.0
+      '@codemirror/lint': 6.7.1
       '@codemirror/state': 6.4.1
       '@codemirror/view': 6.26.3
       '@lezer/common': 1.2.1
-      '@lezer/javascript': 1.4.15
+      '@lezer/javascript': 1.4.16
     dev: false
 
   /@codemirror/lang-json@6.0.1:
@@ -852,8 +852,8 @@ packages:
       crelt: 1.0.6
     dev: false
 
-  /@codemirror/lint@6.7.0:
-    resolution: {integrity: sha512-LTLOL2nT41ADNSCCCCw8Q/UmdAFzB23OUYSjsHTdsVaH0XEo+orhuqbDNWzrzodm14w6FOxqxpmy4LF8Lixqjw==}
+  /@codemirror/lint@6.7.1:
+    resolution: {integrity: sha512-rELba6QJD20/bNXWP/cKTGLrwVEcpa2ViwULCV03ONcY1Je85++7sczVRUlnE4TJMjatx3IJTz6HX4NXi+moXw==}
     dependencies:
       '@codemirror/state': 6.4.1
       '@codemirror/view': 6.26.3
@@ -1124,15 +1124,15 @@ packages:
     engines: {node: ^12.0.0 || ^14.0.0 || >=16.0.0}
     dev: true
 
-  /@eslint/eslintrc@2.1.4:
-    resolution: {integrity: sha512-269Z39MS6wVJtsoUl10L60WdkhJVdPG24Q4eZTH3nnF6lpvSShEK3wQjDX9JRWAUPvPh7COouPpU9IrqaZFvtQ==}
-    engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
+  /@eslint/eslintrc@3.0.2:
+    resolution: {integrity: sha512-wV19ZEGEMAC1eHgrS7UQPqsdEiCIbTKTasEfcXAigzoXICcqZSjBZEHlZwNVvKg6UBCjSlos84XiLqsRJnIcIg==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     dependencies:
       ajv: 6.12.6
       debug: 4.3.4(supports-color@5.5.0)
-      espree: 9.6.1
-      globals: 13.24.0
-      ignore: 5.3.1
+      espree: 10.0.1
+      globals: 14.0.0
+      ignore: 5.3.0
       import-fresh: 3.3.0
       js-yaml: 4.1.0
       minimatch: 3.1.2
@@ -1141,15 +1141,15 @@ packages:
       - supports-color
     dev: true
 
-  /@eslint/eslintrc@3.0.2:
-    resolution: {integrity: sha512-wV19ZEGEMAC1eHgrS7UQPqsdEiCIbTKTasEfcXAigzoXICcqZSjBZEHlZwNVvKg6UBCjSlos84XiLqsRJnIcIg==}
+  /@eslint/eslintrc@3.1.0:
+    resolution: {integrity: sha512-4Bfj15dVJdoy3RfZmmo86RK1Fwzn6SstsvK9JS+BaVKqC6QQQQyXekNaC+g+LKNgkQ+2VhGAzm6hO40AhMR3zQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     dependencies:
       ajv: 6.12.6
       debug: 4.3.4(supports-color@5.5.0)
       espree: 10.0.1
       globals: 14.0.0
-      ignore: 5.3.0
+      ignore: 5.3.1
       import-fresh: 3.3.0
       js-yaml: 4.1.0
       minimatch: 3.1.2
@@ -1826,8 +1826,8 @@ packages:
       '@lezer/lr': 1.4.0
     dev: false
 
-  /@lezer/javascript@1.4.15:
-    resolution: {integrity: sha512-B082ZdjI0vo2AgLqD834GlRTE9gwRX8NzHzKq5uDwEnQ9Dq+A/CEhd3nf68tiNA2f9O+8jS1NeSTUYT9IAqcTw==}
+  /@lezer/javascript@1.4.16:
+    resolution: {integrity: sha512-84UXR3N7s11MPQHWgMnjb9571fr19MmXnr5zTv2XX0gHXXUvW3uPJ8GCjKrfTXmSdfktjRK0ayKklw+A13rk4g==}
     dependencies:
       '@lezer/common': 1.2.1
       '@lezer/highlight': 1.2.0
@@ -2150,7 +2150,7 @@ packages:
   /@polka/url@1.0.0-next.24:
     resolution: {integrity: sha512-2LuNTFBIO0m7kKIQvvPHN6UE63VjpmL9rnEEaOOaiSPbZK+zUOYIzBAWcED+3XYzhYsd/0mD57VdxAEqqV52CQ==}
 
-  /@replit/codemirror-lang-svelte@6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.15)(@lezer/lr@1.4.0):
+  /@replit/codemirror-lang-svelte@6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.16)(@lezer/lr@1.4.0):
     resolution: {integrity: sha512-U2OqqgMM6jKelL0GNWbAmqlu1S078zZNoBqlJBW+retTc5M4Mha6/Y2cf4SVg6ddgloJvmcSpt4hHrVoM4ePRA==}
     peerDependencies:
       '@codemirror/autocomplete': ^6.0.0
@@ -2174,7 +2174,7 @@ packages:
       '@codemirror/view': 6.24.0
       '@lezer/common': 1.2.1
       '@lezer/highlight': 1.2.0
-      '@lezer/javascript': 1.4.15
+      '@lezer/javascript': 1.4.16
       '@lezer/lr': 1.4.0
     dev: false
 
@@ -2540,18 +2540,17 @@ packages:
       p-map: 4.0.0
     dev: true
 
-  /@stylistic/eslint-plugin-js@1.8.0(eslint@9.0.0):
-    resolution: {integrity: sha512-jdvnzt+pZPg8TfclZlTZPiUbbima93ylvQ+wNgHLNmup3obY6heQvgewSu9i2CfS61BnRByv+F9fxQLPoNeHag==}
-    engines: {node: ^16.0.0 || >=18.0.0}
+  /@stylistic/eslint-plugin-js@2.1.0(eslint@9.0.0):
+    resolution: {integrity: sha512-gdXUjGNSsnY6nPyqxu6lmDTtVrwCOjun4x8PUn0x04d5ucLI74N3MT1Q0UhdcOR9No3bo5PGDyBgXK+KmD787A==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: '>=8.40.0'
     dependencies:
       '@types/eslint': 8.56.10
       acorn: 8.11.3
-      escape-string-regexp: 4.0.0
       eslint: 9.0.0
-      eslint-visitor-keys: 3.4.3
-      espree: 9.6.1
+      eslint-visitor-keys: 4.0.0
+      espree: 10.0.1
     dev: true
 
   /@supabase/functions-js@2.1.5:
@@ -2645,7 +2644,7 @@ packages:
       - supports-color
     dev: true
 
-  /@sveltejs/eslint-config@7.0.1(@stylistic/eslint-plugin-js@1.8.0)(eslint-config-prettier@9.1.0)(eslint-plugin-svelte@2.38.0)(eslint-plugin-unicorn@52.0.0)(eslint@9.0.0)(typescript-eslint@7.6.0)(typescript@5.3.3):
+  /@sveltejs/eslint-config@7.0.1(@stylistic/eslint-plugin-js@2.1.0)(eslint-config-prettier@9.1.0)(eslint-plugin-svelte@2.39.0)(eslint-plugin-unicorn@53.0.0)(eslint@9.0.0)(typescript-eslint@7.6.0)(typescript@5.3.3):
     resolution: {integrity: sha512-0c65gMzIRkfSNxVtUmMB/0I0A+ypyIS7aJhXXU7dEdoOEmdN5K+GpGB4ybYBmqODJdZlNRmwNFaKxzzUGBkXQA==}
     peerDependencies:
       '@stylistic/eslint-plugin-js': '>= 1'
@@ -2656,11 +2655,11 @@ packages:
       typescript: '>= 5'
       typescript-eslint: '>= 7.5'
     dependencies:
-      '@stylistic/eslint-plugin-js': 1.8.0(eslint@9.0.0)
+      '@stylistic/eslint-plugin-js': 2.1.0(eslint@9.0.0)
       eslint: 9.0.0
       eslint-config-prettier: 9.1.0(eslint@9.0.0)
-      eslint-plugin-svelte: 2.38.0(eslint@9.0.0)(svelte@packages+svelte)
-      eslint-plugin-unicorn: 52.0.0(eslint@9.0.0)
+      eslint-plugin-svelte: 2.39.0(eslint@9.0.0)(svelte@packages+svelte)
+      eslint-plugin-unicorn: 53.0.0(eslint@9.0.0)
       globals: 15.0.0
       typescript: 5.3.3
       typescript-eslint: 7.6.0(eslint@9.0.0)(typescript@5.3.3)
@@ -2719,7 +2718,7 @@ packages:
       vite: 5.0.13(@types/node@20.11.5)(lightningcss@1.23.0)(sass@1.70.0)
     dev: true
 
-  /@sveltejs/repl@0.6.0(@codemirror/lang-html@6.4.9)(@codemirror/search@6.5.6)(@lezer/common@1.2.1)(@lezer/javascript@1.4.15)(@lezer/lr@1.4.0)(@sveltejs/kit@2.4.3)(svelte@4.2.9):
+  /@sveltejs/repl@0.6.0(@codemirror/lang-html@6.4.9)(@codemirror/search@6.5.6)(@lezer/common@1.2.1)(@lezer/javascript@1.4.16)(@lezer/lr@1.4.0)(@sveltejs/kit@2.4.3)(svelte@4.2.9):
     resolution: {integrity: sha512-NADKN0NZhLlSatTSh5CCsdzgf2KHJFRef/8krA/TVWAWos5kSwmZ5fF0UImuqs61Pu/SiMXksaWNTGTiOtr4fQ==}
     peerDependencies:
       svelte: ^3.54.0 || ^4.0.0-next.0 || ^4.0.0
@@ -2737,7 +2736,7 @@ packages:
       '@jridgewell/sourcemap-codec': 1.4.15
       '@lezer/highlight': 1.2.0
       '@neocodemirror/svelte': 0.0.15(@codemirror/autocomplete@6.12.0)(@codemirror/commands@6.3.3)(@codemirror/language@6.10.1)(@codemirror/lint@6.5.0)(@codemirror/search@6.5.6)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)
-      '@replit/codemirror-lang-svelte': 6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.15)(@lezer/lr@1.4.0)
+      '@replit/codemirror-lang-svelte': 6.0.0(@codemirror/autocomplete@6.12.0)(@codemirror/lang-css@6.2.1)(@codemirror/lang-html@6.4.9)(@codemirror/lang-javascript@6.2.1)(@codemirror/language@6.10.1)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)(@lezer/common@1.2.1)(@lezer/highlight@1.2.0)(@lezer/javascript@1.4.16)(@lezer/lr@1.4.0)
       '@replit/codemirror-vim': 6.1.0(@codemirror/commands@6.3.3)(@codemirror/language@6.10.1)(@codemirror/search@6.5.6)(@codemirror/state@6.4.0)(@codemirror/view@6.24.0)
       '@rich_harris/svelte-split-pane': 1.1.2(svelte@4.2.9)
       '@rollup/browser': 3.29.4
@@ -2932,8 +2931,8 @@ packages:
     dependencies:
       undici-types: 5.26.5
 
-  /@types/node@20.12.7:
-    resolution: {integrity: sha512-wq0cICSkRLVaf3UGLMGItu/PtdY7oaXaI/RVU+xliKVOtRna3PRY57ZDfztpDL0n11vfymMUnXv8QwYCO7L1wg==}
+  /@types/node@20.12.12:
+    resolution: {integrity: sha512-eWLDGF/FOSPtAvEqeRAQ4C8LSA7M1I7i0ky1I8U7kD1J5ITyW3AsRhQrKVoWf5pFKZ2kILsEGJhsI9r93PYnOw==}
     dependencies:
       undici-types: 5.26.5
     dev: true
@@ -3568,10 +3567,10 @@ packages:
     engines: {node: ^6 || ^7 || ^8 || ^9 || ^10 || ^11 || ^12 || >=13.7}
     hasBin: true
     dependencies:
-      caniuse-lite: 1.0.30001614
-      electron-to-chromium: 1.4.751
+      caniuse-lite: 1.0.30001621
+      electron-to-chromium: 1.4.777
       node-releases: 2.0.14
-      update-browserslist-db: 1.0.13(browserslist@4.23.0)
+      update-browserslist-db: 1.0.16(browserslist@4.23.0)
     dev: true
 
   /buffer-crc32@0.2.13:
@@ -3657,8 +3656,8 @@ packages:
     resolution: {integrity: sha512-HMFNotUmLXn71BQxg8cijvqxnIAofforZOwGsxyXJ0qugTdspUF4sPSJ2vhgprHCB996tIDzEq1ubumPDV8ULA==}
     dev: true
 
-  /caniuse-lite@1.0.30001614:
-    resolution: {integrity: sha512-jmZQ1VpmlRwHgdP1/uiKzgiAuGOfLEJsYFP4+GBou/QQ4U6IOJCB4NP1c+1p9RGLpwObcT94jA5/uO+F1vBbog==}
+  /caniuse-lite@1.0.30001621:
+    resolution: {integrity: sha512-+NLXZiviFFKX0fk8Piwv3PfLPGtRqJeq2TiNoUff/qB5KJgwecJTvCXDpmlyP/eCI/GUEmp/h/y5j0yckiiZrA==}
     dev: true
 
   /chai@4.4.1:
@@ -3903,8 +3902,8 @@ packages:
     resolution: {integrity: sha512-U71cyTamuh1CRNCfpGY6to28lxvNwPG4Guz/EVjgf3Jmzv0vlDp1atT9eS5dDjMYHucpHbWns6Lwf3BKz6svdw==}
     engines: {node: '>= 0.6'}
 
-  /core-js-compat@3.37.0:
-    resolution: {integrity: sha512-vYq4L+T8aS5UuFg4UwDhc7YNRWVeVZwltad9C/jV3R2LgVOpS9BDr7l/WL6BN0dbV3k1XejPTHqqEzJgsa0frA==}
+  /core-js-compat@3.37.1:
+    resolution: {integrity: sha512-9TNiImhKvQqSUkOvk/mMRZzOANTiEVC7WaBNhHcKM7x+/5E1l5NvsysR19zuDQScE8k+kfQXWRN3AtS/eOSHpg==}
     dependencies:
       browserslist: 4.23.0
     dev: true
@@ -4255,8 +4254,8 @@ packages:
     resolution: {integrity: sha512-q4lkcbQrUdlzWCUOxk6fwEza6bNCfV12oi4AJph5UibguD1aTfL4uD0nuzFv9hbPANXQMuUS0MxPSHQ1gqq5dg==}
     dev: true
 
-  /electron-to-chromium@1.4.751:
-    resolution: {integrity: sha512-2DEPi++qa89SMGRhufWTiLmzqyuGmNF3SK4+PQetW1JKiZdEpF4XQonJXJCzyuYSA6mauiMhbyVhqYAP45Hvfw==}
+  /electron-to-chromium@1.4.777:
+    resolution: {integrity: sha512-n02NCwLJ3wexLfK/yQeqfywCblZqLcXphzmid5e8yVPdtEcida7li0A5WQKghHNG0FeOMCzeFOzEbtAh5riXFw==}
     dev: true
 
   /emoji-regex@10.3.0:
@@ -4418,6 +4417,11 @@ packages:
     engines: {node: '>=6'}
     dev: true
 
+  /escalade@3.1.2:
+    resolution: {integrity: sha512-ErCHMCae19vR8vQGe50xIsVomy19rg6gFu3+r3jkEO46suLMWBksvVyoGgQV+jOfl84ZSOSlmv6Gxa89PmTGmA==}
+    engines: {node: '>=6'}
+    dev: true
+
   /escape-html@1.0.3:
     resolution: {integrity: sha512-NiSupZ4OeuGwr68lGIeym/ksIZMJodUGOSCZ/FSnTxcrekbvqrgdUxlJOMpijaKZVjAJrWrGs/6Jy8OMuyj9ow==}
     dev: true
@@ -4439,7 +4443,7 @@ packages:
       eslint: '>=6.0.0'
     dependencies:
       eslint: 9.0.0
-      semver: 7.6.0
+      semver: 7.6.2
     dev: true
 
   /eslint-config-prettier@9.1.0(eslint@9.0.0):
@@ -4455,8 +4459,8 @@ packages:
     resolution: {integrity: sha512-BVO83tRo090d6a04cl45Gb761SD79cOT6wKxxWrpsH7Rv8I0SJvc79ijE11vvyxxCMiGUVq/w4NqqPJAHyYfSQ==}
     dev: true
 
-  /eslint-plugin-svelte@2.38.0(eslint@9.0.0)(svelte@packages+svelte):
-    resolution: {integrity: sha512-IwwxhHzitx3dr0/xo0z4jjDlb2AAHBPKt+juMyKKGTLlKi1rZfA4qixMwnveU20/JTHyipM6keX4Vr7LZFYc9g==}
+  /eslint-plugin-svelte@2.39.0(eslint@9.0.0)(svelte@packages+svelte):
+    resolution: {integrity: sha512-FXktBLXsrxbA+6ZvJK2z/sQOrUKyzSg3fNWK5h0reSCjr2fjAsc9ai/s/JvSl4Hgvz3nYVtTIMwarZH5RcB7BA==}
     engines: {node: ^14.17.0 || >=16.0.0}
     peerDependencies:
       eslint: ^7.0.0 || ^8.0.0-0 || ^9.0.0-0
@@ -4471,31 +4475,31 @@ packages:
       eslint: 9.0.0
       eslint-compat-utils: 0.5.0(eslint@9.0.0)
       esutils: 2.0.3
-      known-css-properties: 0.30.0
+      known-css-properties: 0.31.0
       postcss: 8.4.38
       postcss-load-config: 3.1.4(postcss@8.4.38)
       postcss-safe-parser: 6.0.0(postcss@8.4.38)
-      postcss-selector-parser: 6.0.16
-      semver: 7.6.0
+      postcss-selector-parser: 6.1.0
+      semver: 7.6.2
       svelte: link:packages/svelte
-      svelte-eslint-parser: 0.35.0(svelte@packages+svelte)
+      svelte-eslint-parser: 0.36.0(svelte@packages+svelte)
     transitivePeerDependencies:
       - supports-color
       - ts-node
     dev: true
 
-  /eslint-plugin-unicorn@52.0.0(eslint@9.0.0):
-    resolution: {integrity: sha512-1Yzm7/m+0R4djH0tjDjfVei/ju2w3AzUGjG6q8JnuNIL5xIwsflyCooW5sfBvQp2pMYQFSWWCFONsjCax1EHng==}
-    engines: {node: '>=16'}
+  /eslint-plugin-unicorn@53.0.0(eslint@9.0.0):
+    resolution: {integrity: sha512-kuTcNo9IwwUCfyHGwQFOK/HjJAYzbODHN3wP0PgqbW+jbXqpNWxNVpVhj2tO9SixBwuAdmal8rVcWKBxwFnGuw==}
+    engines: {node: '>=18.18'}
     peerDependencies:
       eslint: '>=8.56.0'
     dependencies:
       '@babel/helper-validator-identifier': 7.24.5
       '@eslint-community/eslint-utils': 4.4.0(eslint@9.0.0)
-      '@eslint/eslintrc': 2.1.4
+      '@eslint/eslintrc': 3.1.0
       ci-info: 4.0.0
       clean-regexp: 1.0.0
-      core-js-compat: 3.37.0
+      core-js-compat: 3.37.1
       eslint: 9.0.0
       esquery: 1.5.0
       indent-string: 4.0.0
@@ -4505,7 +4509,7 @@ packages:
       read-pkg-up: 7.0.1
       regexp-tree: 0.1.27
       regjsparser: 0.10.0
-      semver: 7.6.0
+      semver: 7.6.2
       strip-indent: 3.0.0
     transitivePeerDependencies:
       - supports-color
@@ -5088,13 +5092,6 @@ packages:
       process: 0.11.10
     dev: true
 
-  /globals@13.24.0:
-    resolution: {integrity: sha512-AhO5QUcj8llrbG09iWhPU2B204J1xnPeL8kQmVorSsy+Sjj1sk8gIyh6cUocGmH4L0UuhAJy+hJMRA4mgA4mFQ==}
-    engines: {node: '>=8'}
-    dependencies:
-      type-fest: 0.20.2
-    dev: true
-
   /globals@14.0.0:
     resolution: {integrity: sha512-oahGvuMGQlPw/ivIYBjVSrWAfWLBeku5tpPE2fOPLi+WHffIWbuh2tCjhyQhTBPMf5E9jDEH4FOmTYgYwbKwtQ==}
     engines: {node: '>=18'}
@@ -5822,7 +5819,7 @@ packages:
     resolution: {integrity: sha512-o+NO+8WrRiQEE4/7nwRJhN1HWpVmJm511pBHUxPLtp0BUISzlBplORYSmTclCnJvQq2tKu/sgl3xVpkc7ZWuQQ==}
     engines: {node: '>=6'}
 
-  /knip@4.2.1(@types/node@20.12.7)(typescript@5.4.5):
+  /knip@4.2.1(@types/node@20.12.12)(typescript@5.4.5):
     resolution: {integrity: sha512-KG++YCus11YyQQeiBxhXxv6NCJzol4AYER9q1kwZGFw+gwDzG/0Q6MN87McYFN74nGRX4O2xM5CA3TTPcbpn5A==}
     engines: {node: '>=18.6.0'}
     hasBin: true
@@ -5838,7 +5835,7 @@ packages:
       '@pnpm/logger': 5.0.0
       '@pnpm/workspace.pkgs-graph': 2.0.13(@pnpm/logger@5.0.0)
       '@snyk/github-codeowners': 1.1.0
-      '@types/node': 20.12.7
+      '@types/node': 20.12.12
       '@types/picomatch': 2.3.3
       easy-table: 1.2.0
       fast-glob: 3.3.2
@@ -5860,8 +5857,8 @@ packages:
       - domexception
     dev: true
 
-  /known-css-properties@0.30.0:
-    resolution: {integrity: sha512-VSWXYUnsPu9+WYKkfmJyLKtIvaRJi1kXUqVmBACORXZQxT5oZDsoZ2vQP+bQFDnWtpI/4eq3MLoRMjI2fnLzTQ==}
+  /known-css-properties@0.31.0:
+    resolution: {integrity: sha512-sBPIUGTNF0czz0mwGGUoKKJC8Q7On1GPbCSFPfyEsfHb2DyBG0Y4QtV+EVWpINSaiGKZblDNuF5AezxSgOhesQ==}
     dev: true
 
   /levn@0.4.1:
@@ -6880,6 +6877,10 @@ packages:
   /picocolors@1.0.0:
     resolution: {integrity: sha512-1fygroTLlHu66zi26VoTDv8yRgm0Fccecssto+MhsZ0D/DGW2sm8E8AjW7NU5VVTRt5GxbeZ5qBuJr+HyLYkjQ==}
 
+  /picocolors@1.0.1:
+    resolution: {integrity: sha512-anP1Z8qwhkbmu7MFP5iTt+wQKXgwzf7zTyGlcdzabySa9vd0Xt392U0rVmz9poOaBj0uHJKyyo9/upk0HrEQew==}
+    dev: true
+
   /picomatch@2.3.1:
     resolution: {integrity: sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==}
     engines: {node: '>=8.6'}
@@ -6982,8 +6983,8 @@ packages:
       postcss: 8.4.38
     dev: true
 
-  /postcss-selector-parser@6.0.16:
-    resolution: {integrity: sha512-A0RVJrX+IUkVZbW3ClroRWurercFhieevHB38sr2+l9eUClMqome3LmEmnhlNy+5Mr2EYN6B2Kaw9wYdd+VHiw==}
+  /postcss-selector-parser@6.1.0:
+    resolution: {integrity: sha512-UMz42UD0UY0EApS0ZL9o1XnLhSTtvvvLe5Dc2H2O56fvRZi+KulDyf5ctDhhtYJBGKStV2FL1fy6253cmLgqVQ==}
     engines: {node: '>=4'}
     dependencies:
       cssesc: 3.0.0
@@ -7007,7 +7008,7 @@ packages:
     engines: {node: ^10 || ^12 || >=14}
     dependencies:
       nanoid: 3.3.7
-      picocolors: 1.0.0
+      picocolors: 1.0.1
       source-map-js: 1.2.0
     dev: true
 
@@ -7510,6 +7511,12 @@ packages:
       lru-cache: 6.0.0
     dev: true
 
+  /semver@7.6.2:
+    resolution: {integrity: sha512-FNAIBWCx9qcRhoHcgcJ0gvU7SN1lYU2ZXuSfl04bSC5OpvDHFyJCjdNHomPXxjQlCBU67YW64PzY7/VIEH7F2w==}
+    engines: {node: '>=10'}
+    hasBin: true
+    dev: true
+
   /send@0.18.0:
     resolution: {integrity: sha512-qqWzuOjSFOuqPjFe4NOsMLafToQQwBSOEpS+FwEt3A2V3vKubTquT3vmLTQpFgMXp8AlFWFuP1qKaJZOtPpVXg==}
     engines: {node: '>= 0.8.0'}
@@ -8065,11 +8072,11 @@ packages:
       - sugarss
     dev: true
 
-  /svelte-eslint-parser@0.35.0(svelte@packages+svelte):
-    resolution: {integrity: sha512-CtbPseajW0gjwEvHiuzYJkPDjAcHz2FaHt540j6RVYrZgnE6xWkzUBodQ4I3nV+G5AS0Svt8K6aIA/CIU9xT2Q==}
+  /svelte-eslint-parser@0.36.0(svelte@packages+svelte):
+    resolution: {integrity: sha512-/6YmUSr0FAVxW8dXNdIMydBnddPMHzaHirAZ7RrT21XYdgGGZMh0LQG6CZsvAFS4r2Y4ItUuCQc8TQ3urB30mQ==}
     engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
     peerDependencies:
-      svelte: ^3.37.0 || ^4.0.0 || ^5.0.0-next.112
+      svelte: ^3.37.0 || ^4.0.0 || ^5.0.0-next.115
     peerDependenciesMeta:
       svelte:
         optional: true
@@ -8482,11 +8489,6 @@ packages:
     engines: {node: '>=10'}
     dev: true
 
-  /type-fest@0.20.2:
-    resolution: {integrity: sha512-Ne+eE4r0/iWnpAxD852z3A+N0Bt5RN//NjJwRd2VFHEmrywxf5vsZlh4R6lixl6B+wz/8d+maTSAkN1FIkI3LQ==}
-    engines: {node: '>=10'}
-    dev: true
-
   /type-fest@0.6.0:
     resolution: {integrity: sha512-q+MB8nYR1KDLrgr4G5yemftpMC7/QLqVndBmEEdqzmNj5dcFOO4Oo8qlwZE3ULT3+Zim1F8Kq4cBnikNhlCMlg==}
     engines: {node: '>=8'}
@@ -8649,15 +8651,15 @@ packages:
       picocolors: 1.0.0
     dev: true
 
-  /update-browserslist-db@1.0.13(browserslist@4.23.0):
-    resolution: {integrity: sha512-xebP81SNcPuNpPP3uzeW1NYXxI3rxyJzF3pD6sH4jE7o/IX+WtSpwnVU+qIsDPyk0d3hmFQ7mjqc6AtV604hbg==}
+  /update-browserslist-db@1.0.16(browserslist@4.23.0):
+    resolution: {integrity: sha512-KVbTxlBYlckhF5wgfyZXTWnMn7MMZjMu9XG8bPlliUOP9ThaF4QnhP8qrjrH7DRzHfSk0oQv1wToW+iA5GajEQ==}
     hasBin: true
     peerDependencies:
       browserslist: '>= 4.21.0'
     dependencies:
       browserslist: 4.23.0
-      escalade: 3.1.1
-      picocolors: 1.0.0
+      escalade: 3.1.2
+      picocolors: 1.0.1
     dev: true
 
   /uri-js@4.4.1:
diff --git a/sites/svelte-5-preview/package.json b/sites/svelte-5-preview/package.json
index 8325e66a87..e4c4cc3009 100644
--- a/sites/svelte-5-preview/package.json
+++ b/sites/svelte-5-preview/package.json
@@ -53,7 +53,7 @@
     "esm-env": "^1.0.0",
     "marked": "^7.0.2",
     "resolve.exports": "^2.0.2",
-    "svelte-json-tree": "^2.1.0",
+    "svelte-json-tree": "^2.2.0",
     "zimmerframe": "^1.1.1"
   }
 }
diff --git a/sites/svelte-5-preview/src/lib/Output/ReplProxy.js b/sites/svelte-5-preview/src/lib/Output/ReplProxy.js
index a7a57bcb3f..0e45887bd7 100644
--- a/sites/svelte-5-preview/src/lib/Output/ReplProxy.js
+++ b/sites/svelte-5-preview/src/lib/Output/ReplProxy.js
@@ -1,27 +1,35 @@
 let uid = 1;
 
-const noop = () => {};
-
 export default class ReplProxy {
 	/** @type {HTMLIFrameElement} */
 	iframe;
 
 	/** @type {import("./proxy").Handlers} */
-	handlers = {
-		on_fetch_progress: noop,
-		on_console: noop,
-		on_error: noop,
-		on_console_group: noop,
-		on_console_group_collapsed: noop,
-		on_console_group_end: noop,
-		on_unhandled_rejection: noop
-	};
+	handlers;
 
 	/** @type {Map<number, { resolve: (value: any) => void, reject: (value: any) => void }>} */
 	pending_cmds = new Map();
 
-	/** @param {MessageEvent<any>} e */
-	handle_event = (e) => this.handle_repl_message(e);
+	/** @param {MessageEvent<any>} event */
+	handle_event = (event) => {
+		if (event.source !== this.iframe.contentWindow) return;
+
+		const { action, args } = event.data;
+
+		switch (action) {
+			case 'cmd_error':
+			case 'cmd_ok':
+				return this.handle_command_message(event.data);
+			case 'fetch_progress':
+				return this.handlers.on_fetch_progress(args.remaining);
+			case 'error':
+				return this.handlers.on_error(event.data);
+			case 'unhandledrejection':
+				return this.handlers.on_unhandled_rejection(event.data);
+			case 'console':
+				return this.handlers.on_console(event.data);
+		}
+	};
 
 	/**
 	 * @param {HTMLIFrameElement} iframe
@@ -77,35 +85,6 @@ export default class ReplProxy {
 		}
 	}
 
-	/**
-	 * @param {MessageEvent<any>} event
-	 */
-	handle_repl_message(event) {
-		if (event.source !== this.iframe.contentWindow) return;
-
-		const { action, args } = event.data;
-
-		switch (action) {
-			case 'cmd_error':
-			case 'cmd_ok':
-				return this.handle_command_message(event.data);
-			case 'fetch_progress':
-				return this.handlers.on_fetch_progress(args.remaining);
-			case 'error':
-				return this.handlers.on_error(event.data);
-			case 'unhandledrejection':
-				return this.handlers.on_unhandled_rejection(event.data);
-			case 'console':
-				return this.handlers.on_console(event.data);
-			case 'console_group':
-				return this.handlers.on_console_group(event.data);
-			case 'console_group_collapsed':
-				return this.handlers.on_console_group_collapsed(event.data);
-			case 'console_group_end':
-				return this.handlers.on_console_group_end(event.data);
-		}
-	}
-
 	/** @param {string} script */
 	eval(script) {
 		return this.iframe_command('eval', { script });
diff --git a/sites/svelte-5-preview/src/lib/Output/Viewer.svelte b/sites/svelte-5-preview/src/lib/Output/Viewer.svelte
index 2944578830..db506ada3b 100644
--- a/sites/svelte-5-preview/src/lib/Output/Viewer.svelte
+++ b/sites/svelte-5-preview/src/lib/Output/Viewer.svelte
@@ -55,32 +55,36 @@
 				pending_imports = progress;
 			},
 			on_error: (event) => {
-				push_logs({ level: 'error', args: [event.value] });
+				push_logs({ command: 'error', args: [event.value] });
 			},
 			on_unhandled_rejection: (event) => {
 				let error = event.value;
 				if (typeof error === 'string') error = { message: error };
 				error.message = 'Uncaught (in promise): ' + error.message;
-				push_logs({ level: 'error', args: [error] });
+				push_logs({ command: 'error', args: [error] });
 			},
 			on_console: (log) => {
-				if (log.level === 'clear') {
-					clear_logs();
-					push_logs(log);
-				} else if (log.duplicate) {
-					increment_duplicate_log();
-				} else {
-					push_logs(log);
+				switch (log.command) {
+					case 'clear':
+						clear_logs();
+						push_logs(log);
+						break;
+
+					case 'group':
+						group_logs(log);
+						break;
+
+					case 'groupEnd':
+						ungroup_logs();
+						break;
+
+					case 'duplicate':
+						increment_duplicate_log();
+						break;
+
+					default:
+						push_logs(log);
 				}
-			},
-			on_console_group: (action) => {
-				group_logs(action.label, false);
-			},
-			on_console_group_end: () => {
-				ungroup_logs();
-			},
-			on_console_group_collapsed: (action) => {
-				group_logs(action.label, true);
 			}
 		});
 
@@ -202,17 +206,13 @@
 		logs = logs;
 	}
 
-	/**
-	 * @param {string} label
-	 * @param {boolean} collapsed
-	 */
-	function group_logs(label, collapsed) {
-		/** @type {import('./console/console').Log} */
-		const group_log = { level: 'group', label, collapsed, logs: [] };
-		current_log_group.push({ level: 'group', label, collapsed, logs: [] });
+	/** @param {import('./console/console').Log} log */
+	function group_logs(log) {
+		log.logs = [];
+		current_log_group.push(log);
 		// TODO: Investigate
 		log_group_stack.push(current_log_group);
-		current_log_group = group_log.logs ?? [];
+		current_log_group = log.logs;
 		logs = logs;
 	}
 
@@ -284,7 +284,7 @@
 		</div>
 
 		<section slot="panel-body">
-			<Console {logs} {theme} on:clear={clear_logs} />
+			<Console {logs} />
 		</section>
 	</PaneWithPanel>
 
diff --git a/sites/svelte-5-preview/src/lib/Output/console/Console.svelte b/sites/svelte-5-preview/src/lib/Output/console/Console.svelte
index c1adaff32f..e2a880aff8 100644
--- a/sites/svelte-5-preview/src/lib/Output/console/Console.svelte
+++ b/sites/svelte-5-preview/src/lib/Output/console/Console.svelte
@@ -3,12 +3,9 @@
 
 	/** @type {import('./console').Log[]} */
 	export let logs;
-
-	/** @type {'light' | 'dark'} */
-	export let theme;
 </script>
 
-<div class="container" class:dark={theme === 'dark'}>
+<div class="container">
 	{#each logs as log}
 		<ConsoleLine {log} />
 	{/each}
@@ -16,21 +13,34 @@
 
 <style>
 	.container {
+		--error-fg: #da106e;
+		--error-bg: #fff0f0;
+		--error-border: rgb(242, 214, 219);
+		--warning-bg: rgb(254, 251, 218);
+		--warning-border: rgb(242, 232, 163);
 		--json-tree-string-color: var(--sk-code-string);
-	}
-	.dark {
-		--json-tree-property-color: #72a2d3;
-		--json-tree-string-color: #6cd1c7;
-		--json-tree-symbol-color: #6cd1c7;
-		--json-tree-boolean-color: #9681f7;
-		--json-tree-function-color: #e59b6f;
-		--json-tree-number-color: #9681f7;
-		--json-tree-label-color: #9ca0a5;
-		--json-tree-arrow-color: #e8eaed;
-		--json-tree-null-color: #81868a;
-		--json-tree-undefined-color: #81868a;
-		--json-tree-date-color: #9ca0a5;
-		--json-tree-operator-color: #e8eaed;
-		--json-tree-regex-color: #6cd1c7;
+		--json-tree-font-family: var(--sk-font-mono);
+
+		:global(.dark) & {
+			--error-fg: rgb(235, 78, 109);
+			--error-bg: rgb(71, 48, 54);
+			--error-border: rgb(109, 65, 76);
+			--warning-bg: rgb(64, 56, 34);
+			--warning-border: rgb(86, 86, 51);
+
+			--json-tree-property-color: #72a2d3;
+			--json-tree-string-color: #6cd1c7;
+			--json-tree-symbol-color: #6cd1c7;
+			--json-tree-boolean-color: #9681f7;
+			--json-tree-function-color: #e59b6f;
+			--json-tree-number-color: #9681f7;
+			--json-tree-label-color: #9ca0a5;
+			--json-tree-arrow-color: #e8eaed;
+			--json-tree-null-color: #81868a;
+			--json-tree-undefined-color: #81868a;
+			--json-tree-date-color: #9ca0a5;
+			--json-tree-operator-color: #e8eaed;
+			--json-tree-regex-color: #6cd1c7;
+		}
 	}
 </style>
diff --git a/sites/svelte-5-preview/src/lib/Output/console/ConsoleLine.svelte b/sites/svelte-5-preview/src/lib/Output/console/ConsoleLine.svelte
index 4c2be9ef83..f990cdc1be 100644
--- a/sites/svelte-5-preview/src/lib/Output/console/ConsoleLine.svelte
+++ b/sites/svelte-5-preview/src/lib/Output/console/ConsoleLine.svelte
@@ -4,137 +4,164 @@
 
 	/** @type {import('./console').Log} */
 	export let log;
-	export let level = 1;
+	export let depth = 1;
 
 	function toggle_group_collapse() {
 		log.collapsed = !log.collapsed;
 	}
 </script>
 
-{#if log.args && log.level === 'table'}
-	<ConsoleTable data={log.args[0]} columns={log.args[1]} />
+{#if log.command === 'table'}
+	<ConsoleTable data={log.data} columns={log.columns} />
 {/if}
 
-<span class="log console-{log.level}" style="padding-left: {level * 15}px">
-	{#if log.count && log.count > 1}
-		<span class="count">{log.count}x</span>
-	{/if}
-
-	{#if log.level === 'trace' || log.level === 'assert' || log.level === 'group'}
-		<button on:click={toggle_group_collapse}>
-			<span class="arrow" class:expand={!log.collapsed}> ▶️ </span>
-			{#if log.level === 'group'}
-				<span class="title">{log.label}</span>
-			{/if}
-		</button>
-	{/if}
+<div class="{log.command} line" style="--indent: {depth * 15}px">
+	<!-- svelte-ignore a11y_click_events_have_key_events -->
+	<div
+		role="button"
+		tabindex="0"
+		on:click={toggle_group_collapse}
+		class="log"
+		class:expandable={log.stack || log.command === 'group'}
+	>
+		{#if log.count && log.count > 1}
+			<span class="count">{log.count}</span>
+		{/if}
+
+		{#if log.stack || log.command === 'group'}
+			<span class="arrow" class:expand={!log.collapsed}>{'\u25B6'}</span>
+		{/if}
+
+		{#if log.command === 'clear'}
+			<span class="meta">Console was cleared</span>
+		{:else if log.command === 'unclonable'}
+			<span class="meta meta-error">Message could not be cloned. Open devtools to see it</span>
+		{:else if log.command === 'table'}
+			<JSONNode value={log.data} />
+		{:else}
+			{#each log.args ?? [] as arg}
+				<JSONNode value={arg} defaultExpandedLevel={log.expanded ? 1 : 0} />
+			{/each}
+		{/if}
+	</div>
 
-	{#if log.level === 'assert'}
-		<span class="assert">Assertion failed:</span>
+	{#if log.stack && !log.collapsed}
+		<div class="stack">
+			{#each log.stack as line}
+				<span>{line.label}</span>
+				<span class="location">{line.location}</span>
+			{/each}
+		</div>
 	{/if}
 
-	{#if log.level === 'clear'}
-		<span class="info">Console was cleared</span>
-	{:else if log.level === 'unclonable'}
-		<span class="info error">Message could not be cloned. Open devtools to see it</span>
-	{:else if log.level.startsWith('system')}
-		{#each log.args ?? [] as arg}
-			{arg}
-		{/each}
-	{:else if log.args && log.level === 'table'}
-		<JSONNode value={log.args[0]} />
-	{:else}
-		{#each log.args ?? [] as arg}
-			<JSONNode value={arg} />
-		{/each}
-	{/if}
-	{#each new Array(level - 1) as _, idx}
+	{#each new Array(depth - 1) as _, idx}
 		<div class="outline" style="left: {idx * 15 + 15}px"></div>
 	{/each}
-</span>
+</div>
 
-{#if log.level === 'group' && !log.collapsed}
+{#if log.command === 'group' && !log.collapsed}
 	{#each log.logs ?? [] as childLog}
-		<svelte:self log={childLog} level={level + 1} />
+		<svelte:self log={childLog} depth={depth + 1} />
 	{/each}
 {/if}
 
-{#if (log.level === 'trace' || log.level === 'assert') && !log.collapsed}
-	<div class="trace">
-		{#each log.stack?.split('\n').slice(2) ?? '' as stack}
-			<div>{stack.replace(/^\s*at\s+/, '')}</div>
-		{/each}
-	</div>
-{/if}
-
 <style>
-	.log {
-		border-bottom: 0.5px solid var(--sk-back-4);
-		padding: 5px 10px 0px;
-		display: flex;
+	.line {
+		--bg: var(--sk-back-1);
+		--border: var(--sk-back-3);
+		display: block;
 		position: relative;
-		font-size: 12px;
-		font-family: var(--sk-font-mono);
-	}
-
-	.log > :global(*) {
-		margin-right: 10px;
-		font-family: var(--sk-font-mono);
+		width: 100%;
+		text-align: left;
+		border-width: 1px;
+		border-style: solid none none none;
+		border-color: var(--border);
+		background: var(--bg);
 	}
 
-	.console-warn,
-	.console-system-warn {
-		background: hsla(50, 100%, 95%, 0.4);
-		border-color: #fff4c4;
+	.warn {
+		--bg: var(--warning-bg);
+		--border: var(--warning-border);
 	}
 
-	.console-error,
-	.console-assert {
-		background: #fff0f0;
-		border-color: #fed6d7;
+	.error {
+		--bg: var(--error-bg);
+		--border: var(--error-border);
 	}
 
-	.console-group,
-	.arrow {
-		cursor: pointer;
-		user-select: none;
-	}
+	.warn,
+	.error {
+		border-style: solid none;
 
-	.console-trace,
-	.console-assert {
-		border-bottom: none;
+		& + :global(&) {
+			border-top: none;
+		}
 	}
 
-	.console-assert + .trace {
-		background: #fff0f0;
-		border-color: #fed6d7;
+	.group {
+		font-weight: 700;
 	}
 
-	.trace {
-		border-bottom: 1px solid #eee;
+	.log {
+		padding: 5px 10px 5px var(--indent);
+		display: flex;
+		width: 100%;
 		font-size: 12px;
 		font-family: var(--sk-font-mono);
-		padding: 4px 0 2px;
+		align-items: center;
 	}
 
-	.trace > :global(div) {
-		margin-left: 15px;
+	.log.expandable {
+		cursor: pointer;
+		padding-left: calc(var(--indent) + 1em);
 	}
 
-	.count {
-		color: var(--sk-text-3, #999);
+	.stack {
+		display: grid;
+		grid-template-columns: minmax(0, auto) minmax(auto, 1fr);
+		grid-gap: 0 2rem;
 		font-size: 12px;
-		line-height: 1.2;
+		font-family: var(--sk-font-mono);
+		margin: 0 1rem 0.4rem calc(1em + var(--indent));
+		overflow: hidden;
+
+		.location {
+			position: relative;
+			background: var(--bg);
+			&::before {
+				content: '';
+				position: absolute;
+				width: 1rem;
+				height: 100%;
+				left: -1rem;
+				top: 0;
+				background: linear-gradient(to right, transparent, var(--bg));
+			}
+		}
 	}
 
-	.info {
+	.count {
+		position: relative;
+		display: flex;
+		justify-content: center;
+		align-items: center;
+		min-width: 1.5em;
+		height: 1.4em;
+		padding: 0.5em;
+		border-radius: 0.4rem;
+		background-color: var(--sk-text-3, #777);
+		color: var(--sk-back-1);
+		font-size: 1rem;
+	}
+
+	.meta {
 		color: var(--sk-text-2, #666);
 		font-family: var(--sk-font) !important;
 		font-size: 12px;
 	}
 
-	.error {
-		color: #da106e; /* todo make this a var */
+	.meta-error {
+		color: var(--error-fg);
 	}
 
 	.outline {
@@ -146,27 +173,13 @@
 
 	.arrow {
 		position: absolute;
-		font-size: 0.6em;
+		font-size: 0.9rem;
 		transition: 150ms;
 		transform-origin: 50% 50%;
-		transform: translateY(1px) translateX(-50%);
+		transform: translateX(-1.2rem) translateY(-1px);
 	}
 
 	.arrow.expand {
-		transform: translateY(1px) translateX(-50%) rotateZ(90deg);
-	}
-
-	.title {
-		font-family: var(--sk-font-mono);
-		font-size: 13px;
-		font-weight: bold;
-		padding-left: 11px;
-		height: 19px;
-	}
-
-	.assert {
-		padding-left: 11px;
-		font-weight: bold;
-		color: #da106e;
+		transform: translateX(-1.2rem) translateY(0px) rotateZ(90deg);
 	}
 </style>
diff --git a/sites/svelte-5-preview/src/lib/Output/console/ConsoleTable.svelte b/sites/svelte-5-preview/src/lib/Output/console/ConsoleTable.svelte
index ce36a41608..cba9721807 100644
--- a/sites/svelte-5-preview/src/lib/Output/console/ConsoleTable.svelte
+++ b/sites/svelte-5-preview/src/lib/Output/console/ConsoleTable.svelte
@@ -7,28 +7,54 @@
 	/** @type {any} */
 	export let columns;
 
-	const INDEX_KEY = '(index)';
-	const VALUE_KEY = 'Value';
-
-	$: keys = Object.keys(data);
-	$: columns_to_render = columns || get_columns_to_render(data, keys);
+	$: table = create_table(data, columns);
 
 	/**
 	 * @param {any} data
-	 * @param {string[]} keys
+	 * @param {string[]} [custom_columns]
 	 */
-	function get_columns_to_render(data, keys) {
-		const columns = new Set([INDEX_KEY]);
-		for (const key of keys) {
+	function create_table(data, custom_columns) {
+		let has_non_object = false;
+		const columns = new Set();
+
+		if (custom_columns) {
+			custom_columns.forEach((column) => columns.add(column));
+		} else {
+			for (const key in data) {
+				const value = data[key];
+				if (typeof value === 'object') {
+					Object.keys(value).forEach((key) => columns.add(key));
+				} else {
+					has_non_object = true;
+				}
+			}
+		}
+
+		const is_array = Array.isArray(data);
+
+		const rows = Object.keys(data).map((key) => {
 			const value = data[key];
-			if (typeof value === 'object') {
-				Object.keys(value).forEach((key) => columns.add(key));
-			} else {
-				columns.add(VALUE_KEY);
+			const values = [];
+
+			for (const column of columns) {
+				values.push(typeof value === 'object' && column in value ? value[column] : '');
+			}
+
+			if (has_non_object) {
+				values.push(typeof value !== 'object' ? value : '');
 			}
+
+			return {
+				key: is_array ? parseInt(key) : key,
+				values
+			};
+		});
+
+		if (has_non_object) {
+			columns.add('Value');
 		}
 
-		return [...columns];
+		return { columns, rows };
 	}
 </script>
 
@@ -36,24 +62,33 @@
 	<table>
 		<thead>
 			<tr>
-				{#each columns_to_render as column}
+				<th>(index)</th>
+
+				{#each table.columns as column}
 					<th>{column}</th>
 				{/each}
 			</tr>
 		</thead>
+
 		<tbody>
-			{#each keys as key}
+			{#each table.rows as row}
 				<tr>
-					{#each columns_to_render as column}
-						{#if column === INDEX_KEY}
-							<td>{key}</td>
-						{:else if column === VALUE_KEY}
-							<td><JSONNode value={data[key]} /></td>
-						{:else if column in data[key]}
-							<td><JSONNode value={data[key][column]} /></td>
+					<td>
+						{#if typeof row.key === 'string'}
+							{row.key}
 						{:else}
-							<td></td>
+							<JSONNode value={row.key} />
 						{/if}
+					</td>
+
+					{#each row.values as value}
+						<td>
+							{#if typeof value === 'string'}
+								{value}
+							{:else}
+								<JSONNode {value} />
+							{/if}
+						</td>
 					{/each}
 				</tr>
 			{/each}
@@ -63,32 +98,48 @@
 
 <style>
 	.table {
+		--json-tree-font-size: 1.2rem;
+		--json-tree-font-family: var(--sk-font-mono);
 		margin: 8px;
 		overflow: auto;
 		max-height: 200px;
+		border: 1px solid var(--sk-back-4);
+		border-radius: 2px;
+		overscroll-behavior: none;
 	}
+
 	table {
-		font-size: 12px;
-		font-family: var(--sk-font-mono);
 		border-collapse: collapse;
 		line-height: 1;
-		border: 1px solid #aaa;
 	}
+
 	th {
-		background: #f3f3f3;
-		padding: 4px 8px;
-		border: 1px solid #aaa;
+		background: var(--sk-back-3);
+		padding: 0.5rem 1rem;
+		border: none;
 		position: sticky;
+		font-weight: normal;
+		font-size: 1.4rem;
 		top: 0;
 	}
+
 	td {
-		padding: 2px 8px;
+		font-family: var(--sk-font-mono);
+		font-size: 1.2rem;
+		padding: 0.5rem 1rem;
+		border-bottom: none;
+	}
+
+	tr {
+		background: var(--sk-back-1);
 	}
+
 	tr:nth-child(2n) {
-		background: #f2f7fd;
+		background: var(--sk-back-3);
 	}
+
 	th,
 	td {
-		border-right: 1px solid #aaa;
+		border-right: 1px solid var(--sk-back-3);
 	}
 </style>
diff --git a/sites/svelte-5-preview/src/lib/Output/console/console.d.ts b/sites/svelte-5-preview/src/lib/Output/console/console.d.ts
index 5c45fbade6..b69cbc98b2 100644
--- a/sites/svelte-5-preview/src/lib/Output/console/console.d.ts
+++ b/sites/svelte-5-preview/src/lib/Output/console/console.d.ts
@@ -1,19 +1,12 @@
 export type Log = {
-	level:
-		| 'info'
-		| 'warn'
-		| 'error'
-		| 'table'
-		| 'group'
-		| 'trace'
-		| 'assert'
-		| 'clear'
-		| 'unclonable';
+	command: 'info' | 'warn' | 'error' | 'table' | 'group' | 'clear' | 'unclonable';
 	action?: 'console';
 	args?: any[];
 	collapsed?: boolean;
+	expanded?: boolean;
 	count?: number;
 	logs?: Log[];
 	stack?: string;
-	label?: string;
+	data?: any;
+	columns?: string[];
 };
diff --git a/sites/svelte-5-preview/src/lib/Output/proxy.d.ts b/sites/svelte-5-preview/src/lib/Output/proxy.d.ts
index aad35e726e..b3f9fa8d1a 100644
--- a/sites/svelte-5-preview/src/lib/Output/proxy.d.ts
+++ b/sites/svelte-5-preview/src/lib/Output/proxy.d.ts
@@ -1,10 +1,4 @@
 export type Handlers = Record<
-	| 'on_fetch_progress'
-	| 'on_error'
-	| 'on_unhandled_rejection'
-	| 'on_console'
-	| 'on_console_group'
-	| 'on_console_group_collapsed'
-	| 'on_console_group_end',
+	'on_fetch_progress' | 'on_error' | 'on_unhandled_rejection' | 'on_console',
 	(data: any) => void
 >;
diff --git a/sites/svelte-5-preview/src/lib/Output/srcdoc/index.html b/sites/svelte-5-preview/src/lib/Output/srcdoc/index.html
index e00819120b..bd9fdb2110 100644
--- a/sites/svelte-5-preview/src/lib/Output/srcdoc/index.html
+++ b/sites/svelte-5-preview/src/lib/Output/srcdoc/index.html
@@ -67,34 +67,25 @@
 
 		<script>
 			(function () {
-				function handle_message(ev) {
-					let { action, cmd_id } = ev.data;
-					const send_message = (payload) => parent.postMessage({ ...payload }, ev.origin);
-					const send_reply = (payload) => send_message({ ...payload, cmd_id });
-					const send_ok = () => send_reply({ action: 'cmd_ok' });
-					const send_error = (message, stack) =>
-						send_reply({ action: 'cmd_error', message, stack });
-
-					if (action === 'set_theme') {
-						const { theme } = ev.data.args;
-
-						document.body.classList.toggle('dark', theme === 'dark');
-						send_ok();
-					}
+				function send(payload, origin = '*') {
+					parent.postMessage(payload, origin);
+				}
+
+				window.addEventListener('message', ({ origin, data }) => {
+					let { action, cmd_id } = data;
+
+					const reply = (payload) => send({ ...payload, cmd_id }, origin);
+
+					try {
+						if (action === 'set_theme') {
+							document.body.classList.toggle('dark', data.args.theme === 'dark');
+						}
 
-					if (action === 'eval') {
-						try {
-							const { script } = ev.data.args;
-							(0, eval)(script);
-							send_ok();
-						} catch (e) {
-							send_error(e.message, e.stack);
+						if (action === 'eval') {
+							(0, eval)(data.args.script);
 						}
-					}
 
-					if (action === 'catch_clicks') {
-						try {
-							const top_origin = ev.origin;
+						if (action === 'catch_clicks') {
 							document.body.addEventListener('click', (event) => {
 								if (event.which !== 1) return;
 								if (event.metaKey || event.ctrlKey || event.shiftKey) return;
@@ -114,7 +105,7 @@
 
 								event.preventDefault();
 
-								if (el.href.startsWith(top_origin)) {
+								if (el.href.startsWith(origin)) {
 									const url = new URL(el.href);
 									if (url.hash[0] === '#') {
 										window.location.hash = url.hash;
@@ -124,183 +115,170 @@
 
 								window.open(el.href, '_blank');
 							});
-							send_ok();
-						} catch (e) {
-							send_error(e.message, e.stack);
 						}
-					}
-				}
 
-				window.addEventListener('message', handle_message, false);
+						reply({ action: 'cmd_ok' });
+					} catch ({ message, stack }) {
+						reply({ action: 'cmd_error', message, stack });
+					}
+				});
 
 				window.onerror = function (msg, url, lineNo, columnNo, error) {
-					parent.postMessage({ action: 'error', value: error }, '*');
+					send({ action: 'error', value: error });
 				};
 
 				window.addEventListener('unhandledrejection', (event) => {
-					parent.postMessage({ action: 'unhandledrejection', value: event.reason }, '*');
-				});
-
-				let previous = { level: null, args: null };
-
-				['clear', 'log', 'info', 'dir', 'warn', 'error', 'table'].forEach((level) => {
-					const original = console[level];
-					console[level] = (...args) => {
-						const stringifiedArgs = stringify(args);
-						if (previous.level === level && previous.args && previous.args === stringifiedArgs) {
-							parent.postMessage({ action: 'console', level, duplicate: true }, '*');
-						} else {
-							previous = { level, args: stringifiedArgs };
-
-							try {
-								parent.postMessage({ action: 'console', level, args }, '*');
-							} catch (err) {
-								parent.postMessage({ action: 'console', level: 'unclonable' }, '*');
-							}
-						}
-
-						original(...args);
-					};
-				});
-
-				[
-					{ method: 'group', action: 'console_group' },
-					{ method: 'groupEnd', action: 'console_group_end' },
-					{ method: 'groupCollapsed', action: 'console_group_collapsed' }
-				].forEach((group_action) => {
-					const original = console[group_action.method];
-					console[group_action.method] = (label) => {
-						parent.postMessage({ action: group_action.action, label }, '*');
-
-						original(label);
-					};
+					send({ action: 'unhandledrejection', value: event.reason });
 				});
 
+				// Intercept console methods
 				const timers = new Map();
-				const original_time = console.time;
-				const original_timelog = console.timeLog;
-				const original_timeend = console.timeEnd;
-
-				console.time = (label = 'default') => {
-					original_time(label);
-					timers.set(label, performance.now());
-				};
-				console.timeLog = (label = 'default') => {
-					original_timelog(label);
-					const now = performance.now();
-					if (timers.has(label)) {
-						parent.postMessage(
-							{
-								action: 'console',
-								level: 'system-log',
-								args: [`${label}: ${now - timers.get(label)}ms`]
-							},
-							'*'
-						);
-					} else {
-						parent.postMessage(
-							{
-								action: 'console',
-								level: 'system-warn',
-								args: [`Timer '${label}' does not exist`]
-							},
-							'*'
-						);
-					}
-				};
-				console.timeEnd = (label = 'default') => {
-					original_timeend(label);
-					const now = performance.now();
-					if (timers.has(label)) {
-						parent.postMessage(
-							{
-								action: 'console',
-								level: 'system-log',
-								args: [`${label}: ${now - timers.get(label)}ms`]
-							},
-							'*'
-						);
-					} else {
-						parent.postMessage(
-							{
-								action: 'console',
-								level: 'system-warn',
-								args: [`Timer '${label}' does not exist`]
-							},
-							'*'
-						);
-					}
-					timers.delete(label);
-				};
-
-				const original_assert = console.assert;
-				console.assert = (condition, ...args) => {
-					if (condition) {
-						const stack = new Error().stack;
-						parent.postMessage({ action: 'console', level: 'assert', args, stack }, '*');
-					}
-					original_assert(condition, ...args);
-				};
-
-				const counter = new Map();
-				const original_count = console.count;
-				const original_countreset = console.countReset;
-
-				console.count = (label = 'default') => {
-					counter.set(label, (counter.get(label) || 0) + 1);
-					parent.postMessage(
-						{ action: 'console', level: 'system-log', args: `${label}: ${counter.get(label)}` },
-						'*'
-					);
-					original_count(label);
-				};
+				const counters = new Map();
 
-				console.countReset = (label = 'default') => {
-					if (counter.has(label)) {
-						counter.set(label, 0);
-					} else {
-						parent.postMessage(
-							{
-								action: 'console',
-								level: 'system-warn',
-								args: `Count for '${label}' does not exist`
-							},
-							'*'
-						);
+				function log(command, opts) {
+					try {
+						send({ action: 'console', command, ...opts });
+					} catch {
+						send({ action: 'console', command: 'unclonable' });
 					}
-					original_countreset(label);
-				};
-
-				const original_trace = console.trace;
-
-				console.trace = (...args) => {
-					const stack = new Error().stack;
-					parent.postMessage({ action: 'console', level: 'trace', args, stack }, '*');
-					original_trace(...args);
-				};
+				}
 
 				function stringify(args) {
 					try {
 						return JSON.stringify(args, (key, value) => {
 							// if we don't do this, our Set/Map from svelte/reactivity would show up wrong in the console
 							if (value instanceof Map) {
-								return {
-									type: 'Map',
-									value
-								};
+								return { type: 'Map', value };
 							}
+
 							if (value instanceof Set) {
-								return {
-									type: 'Set',
-									value
-								};
+								return { type: 'Set', value };
 							}
+
 							return value;
 						});
 					} catch (error) {
 						return null;
 					}
 				}
+
+				/** @param {string} method */
+				function stack(method) {
+					return new Error().stack
+						.split('\n')
+						.filter((line) => {
+							if (/[(@]about:srcdoc/.test(line)) return false;
+							return true;
+						})
+						.slice(1)
+						.map((line) => {
+							line = line
+								.replace('console[method]', `console.${method}`)
+								.replace(/console\.<computed> \[as \w+\]/, `console.${method}`);
+
+							let match =
+								/^\s+at (.+) \((.+:\d+:\d+)\)/.exec(line) || /^(.+)@(.+:\d+:\d+)?/.exec(line);
+
+							if (match) {
+								return {
+									label: match[1],
+									location: match[2]
+								};
+							}
+
+							return null;
+						})
+						.filter((x) => x);
+				}
+
+				const can_dedupe = ['log', 'info', 'dir', 'warn', 'error', 'assert', 'trace'];
+
+				const methods = {
+					clear: () => log('clear'),
+					// TODO make the command 'push' and the level/type 'info'
+					log: (...args) => log('info', { args }),
+					info: (...args) => log('info', { args }),
+					dir: (...args) => log('info', { args: [args[0]], expanded: true }),
+					warn: (...args) => log('warn', { args, stack: stack('warn'), collapsed: true }),
+					error: (...args) => log('error', { args, stack: stack('error'), collapsed: true }),
+					assert: (condition, ...args) => {
+						if (condition) return;
+						log('error', {
+							args: ['Assertion failed:', ...args],
+							stack: stack('assert'),
+							collapsed: true
+						});
+					},
+					group: (...args) => log('group', { args, collapsed: false }),
+					groupCollapsed: (...args) => log('group', { args, collapsed: true }),
+					groupEnd: () => log('groupEnd'),
+					table: (...args) => {
+						const data = args[0];
+						if (data && typeof data === 'object') {
+							log('table', { data, columns: args[1] });
+						} else {
+							log('info', { args });
+						}
+					},
+					time: (label = 'default') => timers.set(label, performance.now()),
+					timeLog: (label = 'default') => {
+						const now = performance.now();
+						if (timers.has(label)) {
+							log('info', { args: [`${label}: ${now - timers.get(label)}ms`] });
+						} else {
+							log('warn', { args: [`Timer '${label}' does not exist`] });
+						}
+					},
+					timeEnd: (label = 'default') => {
+						const now = performance.now();
+						if (timers.has(label)) {
+							log('info', { args: [`${label}: ${now - timers.get(label)}ms`] });
+						} else {
+							log('warn', { args: [`Timer '${label}' does not exist`] });
+						}
+						timers.delete(label);
+					},
+					count: (label = 'default') => {
+						counters.set(label, (counters.get(label) || 0) + 1);
+						log('info', { args: [`${label}: ${counters.get(label)}`] });
+					},
+					countReset: (label = 'default') => {
+						if (counters.has(label)) {
+							counters.set(label, 0);
+						} else {
+							log('warn', { args: [`Count for '${label}' does not exist`] });
+						}
+					},
+					trace: (...args) => {
+						log('info', {
+							args: args.length === 0 ? 'console.trace' : args,
+							stack: stack('trace'),
+							collapsed: false
+						});
+					}
+				};
+
+				let previous = '';
+
+				for (const method in methods) {
+					const original = console[method];
+
+					console[method] = (...args) => {
+						const stack = new Error().stack;
+
+						if (
+							previous === (previous = stringify({ method, args, stack })) &&
+							can_dedupe.includes(method) &&
+							args.every((arg) => !arg || typeof arg !== 'object')
+						) {
+							send({ action: 'console', command: 'duplicate' });
+						} else {
+							methods[method](...args);
+						}
+
+						original(...args);
+					};
+				}
 			})();
 		</script>
 	</head>

From 44115840bd894ab6281ea61f5dc39021d96da3ae Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Thu, 23 May 2024 08:29:42 +0100
Subject: [PATCH 2/2] chore: cleanup more tests (#11738)

remove awaits in favor of flushSync
---
 .../samples/binding-input/_config.js          |  6 ++--
 .../samples/event-handler/_config.js          |  4 ++-
 .../custom-elements-samples/nested/_config.js |  4 ++-
 .../reflect-attributes-add-remove/_config.js  |  4 +++
 .../reflect-attributes/_config.js             |  2 ++
 .../samples/action-update/_config.js          | 12 ++++---
 .../apply-directives-in-order-2/_config.js    |  8 +++--
 .../apply-directives-in-order/_config.js      |  9 ++++--
 .../await-then-blowback-reactive/_config.js   |  5 +--
 .../binding-indirect-computed/_config.js      |  6 ++--
 .../_config.js                                | 18 ++++++-----
 .../_config.js                                |  8 ++---
 .../_config.js                                |  6 ++--
 .../binding-input-checkbox-group/_config.js   |  6 ++--
 .../samples/binding-input-checkbox/_config.js |  6 ++--
 .../_config.js                                | 12 ++++---
 .../binding-input-group-each-1/_config.js     | 15 ++++-----
 .../binding-input-group-each-10/_config.js    |  9 ++++--
 .../binding-input-group-each-11/_config.js    | 11 ++++---
 .../binding-input-group-each-12/_config.js    |  9 ++++--
 .../binding-input-group-each-13/_config.js    | 21 +++++++------
 .../binding-input-group-each-14/_config.js    | 27 ++++++++--------
 .../binding-input-group-each-15/_config.js    |  9 ++++--
 .../binding-input-group-each-16/_config.js    |  9 ++++--
 .../binding-input-group-each-2/_config.js     |  6 ++--
 .../binding-input-group-each-3/_config.js     | 12 ++++---
 .../binding-input-group-each-4/_config.js     | 31 ++++++++++---------
 .../binding-input-group-each-5/_config.js     | 15 ++++-----
 .../binding-input-group-each-6/_config.js     | 12 ++++---
 .../binding-input-group-each-8/_config.js     | 19 +++++++-----
 .../binding-input-group-each-9/_config.js     | 17 +++++-----
 .../_config.js                                | 20 +++++++-----
 .../_config.js                                | 15 ++++++---
 .../samples/binding-input-number/_config.js   |  9 ++++--
 .../binding-input-radio-group/_config.js      |  6 ++--
 .../_config.js                                |  7 +++--
 .../samples/binding-input-range/_config.js    |  6 ++--
 .../_config.js                                | 10 +++---
 .../_config.js                                | 11 ++++---
 .../binding-input-text-contextual/_config.js  |  7 +++--
 .../_config.js                                |  6 ++--
 .../_config.js                                | 12 ++++---
 .../_config.js                                |  6 ++--
 .../_config.js                                | 15 ++++-----
 .../_config.js                                |  9 +++---
 .../binding-input-text-deep/_config.js        |  6 ++--
 .../samples/binding-input-text/_config.js     |  6 ++--
 .../_config.js                                |  6 ++--
 .../binding-select-multiple/_config.js        |  9 ++++--
 .../binding-select-optgroup/_config.js        |  6 ++--
 .../samples/binding-select/_config.js         |  6 ++--
 .../samples/binding-store-deep/_config.js     |  9 ++++--
 .../samples/binding-store-each/_config.js     |  6 ++--
 .../samples/binding-store/_config.js          |  9 ++++--
 .../samples/binding-textarea/_config.js       |  6 ++--
 .../samples/binding-this-and-value/_config.js |  6 ++--
 .../samples/binding-using-props/_config.js    |  6 ++--
 .../samples/bitmask-overflow-if/_config.js    |  4 ++-
 .../bitmask-overflow-slot-3/_config.js        |  6 ++--
 .../bitmask-overflow-slot-4/_config.js        |  6 ++--
 .../bitmask-overflow-slot-5/_config.js        |  6 ++--
 .../bitmask-overflow-slot-6/_config.js        |  9 ++++--
 .../component-binding-accessors/_config.js    |  9 ++++--
 .../component-binding-blowback-d/_config.js   |  7 +++--
 .../component-binding-blowback-e/_config.js   |  7 +++--
 .../component-binding-blowback-f/_config.js   | 11 +++----
 .../samples/component-binding-deep/_config.js |  7 +++--
 .../component-binding-deep2/_config.js        |  7 +++--
 .../component-binding-each-nested/_config.js  |  7 +++--
 .../samples/component-binding-each/_config.js |  7 +++--
 .../_config.js                                | 11 ++++---
 .../component-binding-nested/_config.js       | 12 ++++---
 .../component-binding-non-leaky/_config.js    |  7 +++--
 .../_config.js                                |  9 ++++--
 .../_config.js                                | 15 ++++++---
 .../_config.js                                |  9 ++++--
 .../component-binding-store/_config.js        | 15 ++++-----
 .../samples/component-binding/_config.js      |  9 ++++--
 .../samples/component-prop-object/_config.js  |  6 ++--
 .../component-slot-attribute-order/_config.js |  6 ++--
 .../component-slot-fallback-2/_config.js      |  9 ++++--
 .../component-slot-fallback-5/_config.js      |  9 ++++--
 .../component-slot-fallback-6/_config.js      |  6 ++--
 .../samples/component-slot-let-b/_config.js   |  6 ++--
 .../samples/component-slot-let-c/_config.js   |  6 ++--
 .../samples/component-slot-let-d/_config.js   |  6 ++--
 .../_config.js                                | 12 ++++---
 .../component-slot-let-scope-3/_config.js     |  6 ++--
 .../component-slot-nested-if/_config.js       |  9 ++++--
 .../_config.js                                |  6 ++--
 .../_config.js                                |  6 ++--
 .../_config.js                                |  6 ++--
 .../_config.js                                | 12 ++++---
 .../_config.js                                | 14 +++++----
 .../component-yield-placement/_config.js      |  6 ++--
 .../samples/const-tag-invalidate/_config.js   | 17 +++++-----
 .../samples/context-api/_config.js            |  9 ++++--
 .../samples/custom-method/_config.js          |  9 ++++--
 .../_config.js                                |  6 ++--
 .../_config.js                                |  7 +++--
 .../dynamic-component-spread-props/_config.js |  9 ++++--
 .../_config.js                                |  7 +++--
 .../each-block-keyed-bind-group/_config.js    | 15 ++++-----
 .../each-block-keyed-dynamic-2/_config.js     |  6 ++--
 .../_config.js                                |  8 +++--
 .../each-block-scope-shadow-bind-2/_config.js |  7 +++--
 .../each-block-scope-shadow-bind-3/_config.js | 19 ++++++------
 .../each-block-scope-shadow-bind-4/_config.js | 15 ++++-----
 .../each-block-scope-shadow-bind/_config.js   |  7 +++--
 .../each-blocks-assignment-2/_config.js       |  7 +++--
 .../samples/each-blocks-assignment/_config.js | 26 +++++++++-------
 .../empty-component-destroy/_config.js        |  7 +++--
 .../event-handler-destructured/_config.js     |  6 ++--
 .../event-handler-dynamic-2/_config.js        | 25 ++++++++++-----
 .../_config.js                                |  6 ++--
 .../_config.js                                | 10 ++++--
 .../event-handler-dynamic-hash/_config.js     | 17 ++++++----
 .../samples/event-handler-dynamic/_config.js  | 16 ++++++----
 .../_config.js                                | 13 +++++---
 .../_config.js                                | 11 +++++--
 .../samples/event-handler-each/_config.js     |  7 +++--
 .../_config.js                                |  9 ++++--
 .../samples/event-handler-sanitize/_config.js |  9 ++++--
 .../samples/event-handler/_config.js          | 11 +++++--
 .../_config.js                                |  6 ++--
 .../samples/if-block-else-update/_config.js   | 19 +++++++++---
 .../inline-style-become-undefined/_config.js  |  7 +++--
 .../_config.js                                |  5 +--
 .../_config.js                                |  9 ++++--
 .../_config.js                                |  7 +++--
 .../_config.js                                |  6 ++--
 .../instrumentation-script-update/_config.js  |  6 ++--
 .../_config.js                                |  9 ++++--
 .../_config.js                                |  7 +++--
 .../_config.js                                |  6 ++--
 .../_config.js                                |  6 ++--
 .../_config.js                                | 15 ++++++---
 .../invalidation-in-if-condition/_config.js   | 12 ++++---
 .../key-block-component-slot/_config.js       |  7 +++--
 .../samples/key-block-static-if/_config.js    |  4 ++-
 .../_config.js                                |  7 +++--
 .../_config.js                                |  6 ++--
 .../nested-destructure-assignment/_config.js  |  6 ++--
 .../samples/prop-no-change/_config.js         |  6 ++--
 .../samples/props-reactive-slot/_config.js    |  6 ++--
 .../samples/props-reassign/_config.js         |  9 ++++--
 .../samples/raw-mustache-as-root/_config.js   | 13 ++++----
 .../raw-mustache-inside-slot/_config.js       | 11 ++++---
 .../reactive-compound-operator/_config.js     |  7 +++--
 .../_config.js                                |  6 ++--
 .../reactive-statement-indirect/_config.js    |  7 +++--
 .../reactive-update-expression/_config.js     |  9 ++++--
 .../reactive-value-mutate-const/_config.js    |  7 +++--
 .../samples/rest-props-reassign/_config.js    |  9 ++++--
 .../rest-props-without-props/_config.js       | 18 ++++++-----
 .../samples/rest-props/_config.js             | 18 ++++++-----
 .../samples/select-lazy-options/_config.js    |  4 ++-
 .../spread-component-with-bind/_config.js     |  6 ++--
 .../_config.js                                | 13 +++++---
 .../_config.js                                |  9 ++++--
 .../store-assignment-updates/_config.js       |  9 ++++--
 .../store-auto-subscribe-implicit/_config.js  |  9 ++++--
 .../samples/store-auto-subscribe/_config.js   |  9 ++++--
 .../store-each-binding-deep/_config.js        |  6 ++--
 .../_config.js                                |  6 ++--
 .../samples/store-each-binding/_config.js     |  6 ++--
 .../samples/store-resubscribe/_config.js      | 12 ++++---
 .../transition-js-events-in-out/_config.js    |  3 ++
 .../_config.js                                |  6 ++--
 .../samples/window-binding-resize/_config.js  |  6 ++--
 .../window-binding-scroll-store/_config.js    |  6 ++--
 .../samples/window-event-context/_config.js   |  7 +++--
 .../samples/window-event/_config.js           |  7 +++--
 .../samples/ambiguous-source/_config.js       |  6 ++--
 .../attribute-spread-reactivitiy/_config.js   |  5 +--
 .../samples/bind-state-property/_config.js    |  7 +++--
 .../samples/bindings-form-reset/_config.js    |  4 ++-
 .../class-frozen-state-object/_config.js      |  9 ++++--
 .../samples/class-frozen-state/_config.js     |  9 ++++--
 .../_config.js                                |  9 ++++--
 .../class-private-frozen-state/_config.js     |  9 ++++--
 .../class-private-state-increment/_config.js  |  9 ++++--
 .../class-private-state-init/_config.js       |  9 ++++--
 .../class-private-state-proxy/_config.js      |  9 ++++--
 .../samples/class-private-state/_config.js    |  9 ++++--
 .../class-state-deep-update/_config.js        | 11 +++++--
 .../samples/class-state-derived-fn/_config.js |  9 ++++--
 .../class-state-derived-private/_config.js    |  9 ++++--
 .../samples/class-state-derived/_config.js    |  9 ++++--
 .../samples/class-state-increment/_config.js  |  9 ++++--
 .../class-state-init-conflict/_config.js      |  9 ++++--
 .../class-state-init-eager-2/_config.js       |  9 ++++--
 .../class-state-init-eager-3/_config.js       |  9 ++++--
 .../samples/class-state-init-eager/_config.js |  9 ++++--
 .../samples/class-state-init/_config.js       |  9 ++++--
 .../samples/class-state-proxy/_config.js      |  9 ++++--
 .../class-state-public-private/_config.js     |  9 ++++--
 .../class-state-with-literal/_config.js       |  9 ++++--
 .../samples/class-state/_config.js            |  9 ++++--
 .../component-let-directive/_config.js        |  6 ++--
 .../samples/derived-direct/_config.js         |  6 ++--
 .../samples/derived-fn-destructure/_config.js |  6 ++--
 .../samples/derived-fn/_config.js             |  6 ++--
 .../derived-indirect-arrow-fn/_config.js      |  4 ++-
 .../samples/derived-indirect-fn-2/_config.js  |  6 ++--
 .../samples/derived-indirect-fn/_config.js    |  6 ++--
 .../samples/derived-proxy/_config.js          |  9 ++++--
 .../destructure-derived-event/_config.js      |  6 ++--
 .../samples/each-mutation/_config.js          | 15 ++++-----
 .../runtime-runes/samples/effect/_config.js   |  5 +--
 .../samples/effects-order/_config.js          |  5 +--
 .../samples/event-arguments-2/_config.js      |  5 +--
 .../samples/event-arguments/_config.js        |  5 +--
 .../event-attribute-after-binding/_config.js  |  9 ++++--
 .../event-attribute-after-spread/_config.js   |  6 ++--
 .../event-attribute-capture/_config.js        |  5 +--
 .../event-attribute-spread-capture/_config.js |  5 +--
 .../samples/event-attribute-window/_config.js |  5 +--
 .../samples/event-exported/_config.js         |  7 +++--
 .../samples/event-listener-spread/_config.js  |  5 +--
 .../_config.js                                |  7 +++--
 .../samples/exports-1/_config.js              |  9 +++---
 .../samples/exports-2/_config.js              |  9 +++---
 .../samples/exports-3/_config.js              |  5 +--
 .../samples/inspect-derived/_config.js        |  7 +++--
 .../samples/invalidate-effect/_config.js      |  5 +--
 .../samples/mutation-both/_config.js          | 15 ++++++---
 .../runtime-runes/samples/mutation/_config.js |  9 ++++--
 .../nested-destructure-assignment/_config.js  |  6 ++--
 .../samples/not-actual-runes/_config.js       |  6 ++--
 .../samples/pre-effect/_config.js             |  5 +--
 .../samples/props-alias/_config.js            |  5 +--
 .../samples/props-bound-fallback/_config.js   |  6 ++--
 .../samples/props-bound-to-normal/_config.js  | 16 ++++++----
 .../samples/props-bound/_config.js            |  5 +--
 .../props-default-value-behavior/_config.js   | 19 +++++++-----
 .../samples/props-spread-fallback/_config.js  | 15 ++++++---
 .../samples/readonly-state-replace/_config.js |  5 +--
 .../samples/readonly-state/_config.js         |  5 +--
 .../runes-in-module-context/_config.js        |  6 ++--
 .../_config.js                                |  6 ++--
 .../snippet-argument-destructured/_config.js  |  6 ++--
 .../snippet-argument-multiple/_config.js      |  6 ++--
 .../samples/snippet-argument/_config.js       |  6 ++--
 .../snippet-complicated-defaults/_config.js   | 16 +++++++---
 .../samples/snippet-const/_config.js          |  9 ++++--
 .../samples/snippet-expressions/_config.js    |  6 ++--
 .../snippet-optional-arguments/_config.js     |  4 ++-
 .../samples/snippet-prop-explicit/_config.js  |  6 ++--
 .../samples/snippet-prop-implicit/_config.js  |  6 ++--
 .../samples/snippet-prop-reactive/_config.js  |  6 ++--
 .../samples/snippet-reactive/_config.js       |  6 ++--
 .../samples/state-snapshot/_config.js         |  6 ++--
 .../samples/state-space/_config.js            |  6 ++--
 .../samples/state-undefined/_config.js        |  7 +++--
 .../store-subscribe-effect-init/_config.js    |  9 ++++--
 .../samples/typescript/_config.js             |  6 ++--
 .../samples/untracked/_config.js              | 12 ++++---
 .../samples/wrapped-$state-2/_config.js       |  6 ++--
 .../samples/wrapped-$state/_config.js         |  9 ++++--
 260 files changed, 1435 insertions(+), 818 deletions(-)

diff --git a/packages/svelte/tests/hydration/samples/binding-input/_config.js b/packages/svelte/tests/hydration/samples/binding-input/_config.js
index f30b4acac6..ebb48abec6 100644
--- a/packages/svelte/tests/hydration/samples/binding-input/_config.js
+++ b/packages/svelte/tests/hydration/samples/binding-input/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { assert_ok, test } from '../../test';
 
 export default test({
@@ -12,11 +13,12 @@ export default test({
 		};
 	},
 
-	async test(assert, target, _, component, window) {
+	test(assert, target, _, component, window) {
 		const input = target.querySelector('input');
 		assert_ok(input);
 		input.value = 'everybody';
-		await input.dispatchEvent(new window.Event('input'));
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.equal(component.name, 'everybody');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/hydration/samples/event-handler/_config.js b/packages/svelte/tests/hydration/samples/event-handler/_config.js
index f76ae62825..282670258c 100644
--- a/packages/svelte/tests/hydration/samples/event-handler/_config.js
+++ b/packages/svelte/tests/hydration/samples/event-handler/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { assert_ok, test } from '../../test';
 
 export default test({
@@ -16,7 +17,8 @@ export default test({
 	async test(assert, target, _, component, window) {
 		const button = target.querySelector('button');
 		assert_ok(button);
-		await button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.ok(component.clicked);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-browser/custom-elements-samples/nested/_config.js b/packages/svelte/tests/runtime-browser/custom-elements-samples/nested/_config.js
index 1c6926be17..f184fd5d99 100644
--- a/packages/svelte/tests/runtime-browser/custom-elements-samples/nested/_config.js
+++ b/packages/svelte/tests/runtime-browser/custom-elements-samples/nested/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../assert';
 const tick = () => Promise.resolve();
 
@@ -18,7 +19,8 @@ export default test({
 		assert.equal(p.innerHTML, 'Context works');
 		assert.equal(getComputedStyle(button).color, 'rgb(255, 0, 0)');
 
-		await button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+		button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.equal(el.counter.count, 1);
 		assert.equal(button.innerHTML, 'count: 1');
diff --git a/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes-add-remove/_config.js b/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes-add-remove/_config.js
index d0ac2cd9cf..7463e8287f 100644
--- a/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes-add-remove/_config.js
+++ b/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes-add-remove/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../assert';
 const tick = () => Promise.resolve();
 
@@ -6,15 +7,18 @@ export default test({
 		const element = document.createElement('custom-element');
 		target.appendChild(element);
 		await tick();
+		flushSync();
 
 		/** @type {any} */
 		const el = target.querySelector('custom-element');
 		el.shadowRoot.querySelector('button').click();
 		await tick();
+		flushSync();
 
 		assert.equal(el.getAttribute('aria-expanded'), '');
 		el.shadowRoot.querySelector('button').click();
 		await tick();
+		flushSync();
 
 		assert.equal(el.getAttribute('aria-expanded'), null);
 	}
diff --git a/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes/_config.js b/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes/_config.js
index 46fc009bd4..62930c2872 100644
--- a/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes/_config.js
+++ b/packages/svelte/tests/runtime-browser/custom-elements-samples/reflect-attributes/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../assert';
 const tick = () => Promise.resolve();
 
@@ -23,6 +24,7 @@ export default test({
 		assert.equal(getComputedStyle(inner_p).color, 'rgb(255, 255, 255)');
 
 		button.click();
+		flushSync();
 		await tick();
 		await tick();
 
diff --git a/packages/svelte/tests/runtime-legacy/samples/action-update/_config.js b/packages/svelte/tests/runtime-legacy/samples/action-update/_config.js
index 1c1dcacf63..a3fcb4232e 100644
--- a/packages/svelte/tests/runtime-legacy/samples/action-update/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/action-update/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -5,7 +6,7 @@ export default test({
 		<button>action</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
@@ -13,7 +14,8 @@ export default test({
 		const leave = new window.MouseEvent('mouseleave');
 		const ctrlPress = new window.KeyboardEvent('keydown', { ctrlKey: true });
 
-		await button.dispatchEvent(enter);
+		button.dispatchEvent(enter);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await window.dispatchEvent(ctrlPress);
+		window.dispatchEvent(ctrlPress);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -31,7 +34,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(leave);
+		button.dispatchEvent(leave);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order-2/_config.js
index 62734c059b..d414ae1f24 100644
--- a/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /** @type {string[]} */
@@ -9,14 +10,15 @@ export default test({
 		return { value };
 	},
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const inputs = target.querySelectorAll('input');
 
-		const event = new window.Event('input');
+		const event = new window.Event('input', { bubbles: true });
 
 		for (const input of inputs) {
 			input.value = 'h';
-			await input.dispatchEvent(event);
+			input.dispatchEvent(event);
+			flushSync();
 		}
 
 		// Svelte 5 breaking change, use:action now fires
diff --git a/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order/_config.js b/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order/_config.js
index aa9ce53877..aea50afafd 100644
--- a/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/apply-directives-in-order/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,13 +16,14 @@ export default test({
 		<p></p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		const event = new window.Event('input');
 		input.value = 'h';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(input.value, 'H');
 		assert.htmlEqual(
@@ -33,7 +35,8 @@ export default test({
 		);
 
 		input.value = 'he';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 		assert.equal(input.value, 'HE');
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/await-then-blowback-reactive/_config.js b/packages/svelte/tests/runtime-legacy/samples/await-then-blowback-reactive/_config.js
index 2b8ba803da..665b8d94b6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/await-then-blowback-reactive/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/await-then-blowback-reactive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -17,8 +18,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[1].selected = true;
-		await select.dispatchEvent(change);
-		await Promise.resolve();
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.equal(span.textContent, 'b');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-indirect-computed/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-indirect-computed/_config.js
index 99ec25dd9c..d6ad620356 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-indirect-computed/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-indirect-computed/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -13,7 +14,7 @@ export default test({
 		</select>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const select = target.querySelector('select');
 		ok(select);
 		const options = target.querySelectorAll('option');
@@ -21,7 +22,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[1].selected = true;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.equal(component.selected.letter, 'B');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual-b/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual-b/_config.js
index 35946383b7..ceb6c8b72e 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual-b/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual-b/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -25,17 +26,17 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = [...target.querySelectorAll('input')];
 
 		const event = new window.Event('change');
 
 		inputs[1].checked = true;
-		await inputs[1].dispatchEvent(event);
+		inputs[1].dispatchEvent(event);
+		flushSync();
 
-		await component.clear();
-
-		await Promise.resolve();
+		component.clear();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -46,9 +47,10 @@ export default test({
 		);
 
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
-
-		await component.clear();
+		inputs[2].dispatchEvent(event);
+		flushSync();
+		component.clear();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual/_config.js
index 775ee643c7..c5fd2f7b49 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-deep-contextual/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -37,7 +38,7 @@ export default test({
 		<p>1 completed</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = [...target.querySelectorAll('input')];
 
 		assert.ok(inputs[0].checked);
@@ -47,9 +48,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[1].checked = true;
-		await inputs[1].dispatchEvent(event);
-		// Wait for the DOM to update
-		await Promise.resolve();
+		inputs[1].dispatchEvent(event);
+		flushSync();
 
 		assert.equal(component.numCompleted, 2);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group-outside-each/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group-outside-each/_config.js
index 5be1d9b38d..489584127d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group-outside-each/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group-outside-each/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 const values = [{ name: 'Alpha' }, { name: 'Beta' }, { name: 'Gamma' }];
@@ -37,7 +38,7 @@ export default test({
 
 		<p>Beta</p>`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, false);
 		assert.equal(inputs[1].checked, true);
@@ -46,7 +47,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group/_config.js
index ee508a564e..c669bbb21d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox-group/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 const values = [{ name: 'Alpha' }, { name: 'Beta' }, { name: 'Gamma' }];
@@ -37,7 +38,7 @@ export default test({
 
 		<p>Beta</p>`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		let inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, false);
 		assert.equal(inputs[1].checked, true);
@@ -46,7 +47,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox/_config.js
index 813c12be1b..1d8a208682 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-checkbox/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>true</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
@@ -24,7 +25,8 @@ export default test({
 		const event = new window.Event('change');
 
 		input.checked = false;
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-duplicate-value/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-duplicate-value/_config.js
index 6e9445ca0c..6d3c494d0d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-duplicate-value/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-duplicate-value/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -19,7 +20,7 @@ export default test({
 		<input type='checkbox' value='d'>d<br>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		const p = target.querySelector('p');
 		ok(p);
@@ -37,7 +38,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(p.innerHTML, 'Checked: a');
 
@@ -52,7 +54,8 @@ export default test({
 		assert.equal(inputs[7].checked, false);
 
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(p.innerHTML, 'Checked: a,d');
 
@@ -67,7 +70,8 @@ export default test({
 		assert.equal(inputs[7].checked, true);
 
 		inputs[4].checked = false;
-		await inputs[4].dispatchEvent(event);
+		inputs[4].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(p.innerHTML, 'Checked: d');
 
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-1/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-1/_config.js
index 47362f973b..9240723738 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-1/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-1/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /** @type {Array<{ name: string }>} */
@@ -112,7 +113,7 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, false);
 		assert.equal(inputs[1].checked, true);
@@ -127,8 +128,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -181,8 +182,8 @@ export default test({
 		`
 		);
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -236,8 +237,8 @@ export default test({
 		);
 
 		inputs[8].checked = false;
-		await inputs[8].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[8].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-10/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-10/_config.js
index 86dc7d397c..4b573e2527 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-10/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-10/_config.js
@@ -1,16 +1,19 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // https://github.com/sveltejs/svelte/issues/7633
 export default test({
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		let inputs = target.querySelectorAll('input');
 
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, false);
 		assert.equal(inputs[2].checked, false);
 
-		await component.moveDown(0);
-		await component.moveDown(1);
+		component.moveDown(0);
+		flushSync();
+		component.moveDown(1);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-11/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-11/_config.js
index 3ab329511d..64d0fd8f93 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-11/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-11/_config.js
@@ -1,8 +1,9 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // https://github.com/sveltejs/svelte/issues/6112
 export default test({
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		let inputs = target.querySelectorAll('input');
 
 		/** @param {Set<number>} set */
@@ -45,8 +46,8 @@ export default test({
 
 		// dom to value
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		check(new Set([0, 3, 5, 6]));
 		assert.equal(component.pipelineOperations[1].operation.args[1].value, 'd');
@@ -84,8 +85,8 @@ export default test({
 		check(new Set([0, 3, 5, 6]));
 
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[2].dispatchEvent(event);
+		flushSync();
 
 		check(new Set([0, 2, 5, 6]));
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-12/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-12/_config.js
index b3fb0e7bc1..14b8030d89 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-12/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-12/_config.js
@@ -1,8 +1,9 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // https://github.com/sveltejs/svelte/issues/6112
 export default test({
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		let inputs = target.querySelectorAll('input');
 
 		/** @param {Set<number>} set */
@@ -45,7 +46,8 @@ export default test({
 
 		// dom to value
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		check(new Set([0, 2, 3]));
 		assert.deepEqual(component.pipelineOperations[1].operation.args[1].value, ['c', 'd']);
@@ -83,7 +85,8 @@ export default test({
 		check(new Set([0, 2, 3]));
 
 		inputs[5].checked = true;
-		await inputs[5].dispatchEvent(event);
+		inputs[5].dispatchEvent(event);
+		flushSync();
 
 		check(new Set([0, 2, 3, 5]));
 		assert.deepEqual(component.pipelineOperations[1].operation.args[0].value, ['b']);
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-13/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-13/_config.js
index 67dacfa99c..7fba86ef34 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-13/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-13/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [input1, input2] = /** @type {NodeListOf<HTMLInputElement>} */ (
 			target.querySelectorAll('input[type=text]')
 		);
@@ -12,26 +13,28 @@ export default test({
 		const event = new window.Event('input');
 
 		input1.value = 'world';
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.equal(radio.checked, true);
 
 		input2.value = 'foo';
-		await input2.dispatchEvent(event);
-		await Promise.resolve();
+		input2.dispatchEvent(event);
+		flushSync();
 		assert.equal(radio.checked, false);
 
 		input1.value = 'foo';
-		await input1.dispatchEvent(event);
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.equal(radio.checked, true);
 
 		input1.value = 'bar';
-		await input1.dispatchEvent(event);
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.equal(radio.checked, false);
 
 		input2.value = 'bar';
-		await input2.dispatchEvent(event);
-		await Promise.resolve();
+		input2.dispatchEvent(event);
+		flushSync();
 		assert.equal(radio.checked, true);
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-14/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-14/_config.js
index 96d98b24c8..a0649c44de 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-14/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-14/_config.js
@@ -1,39 +1,40 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [input1, input2, input3, input4] = target.querySelectorAll('input');
 		const [p] = target.querySelectorAll('p');
 		const event = new window.Event('change');
 
 		input1.checked = true;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1a"]');
 
 		input2.checked = true;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1a","1b"]');
 
 		input3.checked = true;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1a","1b","2a"]');
 
 		input4.checked = true;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1a","1b","2a","2b"]');
 
 		input1.checked = false;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1b","2a","2b"]');
 
 		input3.checked = false;
-		await input1.dispatchEvent(event);
-		await Promise.resolve();
+		input1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(p.innerHTML, '["1b","2b"]');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-15/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-15/_config.js
index 54ddd20af1..a7996e46ff 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-15/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-15/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const checkboxes = /** @type {NodeListOf<HTMLInputElement>} */ (
 			target.querySelectorAll('input[type="checkbox"]')
 		);
@@ -10,12 +11,14 @@ export default test({
 		assert.isTrue(checkboxes[1].checked);
 		assert.isFalse(checkboxes[2].checked);
 
-		await checkboxes[1].click();
+		checkboxes[1].click();
+		flushSync();
 
 		const noChecked = target.querySelector('#output')?.innerHTML;
 		assert.equal(noChecked, '');
 
-		await checkboxes[1].click();
+		checkboxes[1].click();
+		flushSync();
 
 		const oneChecked = target.querySelector('#output')?.innerHTML;
 		assert.equal(oneChecked, 'Mint choc chip');
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-16/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-16/_config.js
index 54ddd20af1..a7996e46ff 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-16/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-16/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const checkboxes = /** @type {NodeListOf<HTMLInputElement>} */ (
 			target.querySelectorAll('input[type="checkbox"]')
 		);
@@ -10,12 +11,14 @@ export default test({
 		assert.isTrue(checkboxes[1].checked);
 		assert.isFalse(checkboxes[2].checked);
 
-		await checkboxes[1].click();
+		checkboxes[1].click();
+		flushSync();
 
 		const noChecked = target.querySelector('#output')?.innerHTML;
 		assert.equal(noChecked, '');
 
-		await checkboxes[1].click();
+		checkboxes[1].click();
+		flushSync();
 
 		const oneChecked = target.querySelector('#output')?.innerHTML;
 		assert.equal(oneChecked, 'Mint choc chip');
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-2/_config.js
index 4ec313aed7..ad5b33fef4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -27,7 +28,7 @@ export default test({
 
 		<p>1, 2, 3</p>`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, true);
@@ -36,7 +37,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = false;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-3/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-3/_config.js
index 47c73ea56a..84b783df75 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-3/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-3/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /** @type {Array<{ name: string }>} */
@@ -110,7 +111,7 @@ export default test({
 			<p>Gamma</p>
 		</div>
 	`,
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 
 		assert.equal(inputs[0].checked, false);
@@ -126,7 +127,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -179,7 +181,8 @@ export default test({
 		`
 		);
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -233,7 +236,8 @@ export default test({
 		);
 
 		inputs[8].checked = false;
-		await inputs[8].dispatchEvent(event);
+		inputs[8].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-4/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-4/_config.js
index 27e13fbbf2..1a78e91214 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-4/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-4/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -37,7 +38,7 @@ export default test({
 		<label><input type="checkbox" value="3" checked> 3</label>
 		<p>3</p>
 	`,
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, false);
@@ -58,8 +59,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[2].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -84,8 +85,8 @@ export default test({
 		);
 
 		inputs[9].checked = true;
-		await inputs[9].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[9].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -110,24 +111,24 @@ export default test({
 		);
 
 		inputs[4].checked = false;
-		await inputs[4].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[4].dispatchEvent(event);
+		flushSync();
 
 		inputs[5].checked = true;
-		await inputs[5].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[5].dispatchEvent(event);
+		flushSync();
 
 		inputs[6].checked = true;
-		await inputs[6].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[6].dispatchEvent(event);
+		flushSync();
 
 		inputs[7].checked = true;
-		await inputs[7].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[7].dispatchEvent(event);
+		flushSync();
 
 		inputs[11].checked = false;
-		await inputs[11].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[11].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-5/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-5/_config.js
index ccd1f8f26b..08af96a844 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-5/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-5/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -37,7 +38,7 @@ export default test({
 		<label><input type="checkbox" value="3"> 3</label>
 		<p>1</p>
 	`,
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, false);
@@ -58,8 +59,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[2].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -84,8 +85,8 @@ export default test({
 		);
 
 		inputs[8].checked = true;
-		await inputs[8].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[8].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -150,8 +151,8 @@ export default test({
 		assert.equal(inputs[11].checked, false);
 
 		inputs[5].checked = false;
-		await inputs[5].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[5].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-6/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-6/_config.js
index 4dff6b2ce2..b4cf9e7ed6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-6/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-6/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<label><input type="checkbox" value="z"> z</label>
 		<p></p>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, false);
 		assert.equal(inputs[1].checked, false);
@@ -32,7 +33,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
+		inputs[2].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -53,7 +55,8 @@ export default test({
 		);
 
 		inputs[4].checked = true;
-		await inputs[4].dispatchEvent(event);
+		inputs[4].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -74,7 +77,8 @@ export default test({
 		);
 
 		inputs[5].checked = true;
-		await inputs[5].dispatchEvent(event);
+		inputs[5].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-8/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-8/_config.js
index 865201f062..384ca0a20c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-8/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-8/_config.js
@@ -1,8 +1,9 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // https://github.com/sveltejs/svelte/issues/7884
 export default test({
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		let inputs = target.querySelectorAll('input');
 
 		assert.htmlEqual(
@@ -27,11 +28,14 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 		inputs[2].checked = true;
-		await inputs[2].dispatchEvent(event);
+		inputs[2].dispatchEvent(event);
+		flushSync();
 		inputs[3].checked = true;
-		await inputs[3].dispatchEvent(event);
+		inputs[3].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -52,8 +56,8 @@ export default test({
 		`
 		);
 
-		await component.update();
-		await Promise.resolve();
+		component.update();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -70,7 +74,8 @@ export default test({
 
 		inputs = target.querySelectorAll('input');
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-9/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-9/_config.js
index 1554c3a7b7..b566e31cb9 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-9/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-each-9/_config.js
@@ -1,18 +1,19 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // https://github.com/sveltejs/svelte/issues/7633
 export default test({
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		let inputs = target.querySelectorAll('input');
 
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, false);
 		assert.equal(inputs[2].checked, false);
 
-		await component.moveDown(0);
-		await component.moveDown(1);
-
-		await Promise.resolve();
+		component.moveDown(0);
+		flushSync();
+		component.moveDown(1);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -34,13 +35,15 @@ export default test({
 		assert.equal(inputs[1].checked, false);
 		assert.equal(inputs[2].checked, true);
 
-		await (component.current = 'b');
+		component.current = 'b';
+		flushSync();
 
 		assert.equal(inputs[0].checked, true);
 		assert.equal(inputs[1].checked, false);
 		assert.equal(inputs[2].checked, false);
 
-		await component.moveDown(1);
+		component.moveDown(1);
+		flushSync();
 
 		// after shifting order, should still keep the correct radio checked
 		inputs = target.querySelectorAll('input');
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-1/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-1/_config.js
index 778cb49df9..d91a7ebadb 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-1/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-1/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 		const clickEvent = new window.Event('click', { bubbles: true });
@@ -27,24 +28,29 @@ export default test({
 		validate_inputs(true, true);
 
 		input1.checked = false;
-		await input1.dispatchEvent(changeEvent);
+		input1.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, ['b']);
 
 		input2.checked = false;
-		await input2.dispatchEvent(changeEvent);
+		input2.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, []);
 
 		input1.checked = true;
 		input2.checked = true;
-		await input1.dispatchEvent(changeEvent);
-		await input2.dispatchEvent(changeEvent);
+		input1.dispatchEvent(changeEvent);
+		input2.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, ['a', 'b']);
 
-		await button.dispatchEvent(clickEvent);
+		button.dispatchEvent(clickEvent);
+		flushSync();
 		assert.deepEqual(component.test, ['a', 'b']); // should it be ['a'] only? valid arguments for both outcomes
 
 		input1.checked = false;
-		await input1.dispatchEvent(changeEvent);
+		input1.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, []);
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-2/_config.js
index 0676ab990f..8647d33f05 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-group-if-gh-8372-2/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 		const clickEvent = new window.Event('click', { bubbles: true });
@@ -27,18 +28,22 @@ export default test({
 		validate_inputs(false, true);
 
 		input1.checked = true;
-		await input1.dispatchEvent(changeEvent);
+		input1.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, 'a');
 
 		input2.checked = true;
-		await input2.dispatchEvent(changeEvent);
+		input2.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, 'b');
 
-		await button.dispatchEvent(clickEvent);
+		button.dispatchEvent(clickEvent);
+		flushSync();
 		assert.deepEqual(component.test, 'b'); // should it be undefined? valid arguments for both outcomes
 
 		input1.checked = true;
-		await input1.dispatchEvent(changeEvent);
+		input1.dispatchEvent(changeEvent);
+		flushSync();
 		assert.deepEqual(component.test, 'a');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-number/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-number/_config.js
index ac089e8797..4c0b68ecb9 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-number/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-number/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>number 42</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, '42');
@@ -23,7 +24,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = '43';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(component.count, 43);
 		assert.htmlEqual(
@@ -46,7 +48,8 @@ export default test({
 
 		// empty string should be treated as null
 		input.value = '';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(component.count, null);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-radio-group/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-radio-group/_config.js
index 6a34d7cd5b..b0d5064383 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-radio-group/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-radio-group/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 const values = [{ name: 'Alpha' }, { name: 'Beta' }, { name: 'Gamma' }];
@@ -37,7 +38,7 @@ export default test({
 
 		<p>Beta</p>`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 		assert.equal(inputs[0].checked, false);
 		assert.equal(inputs[1].checked, true);
@@ -46,7 +47,8 @@ export default test({
 		const event = new window.Event('change');
 
 		inputs[0].checked = true;
-		await inputs[0].dispatchEvent(event);
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-range-change-with-max/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-range-change-with-max/_config.js
index c56f2d6d6f..1c5a41ced3 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-range-change-with-max/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-range-change-with-max/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -13,7 +14,7 @@ export default test({
 		<p>10 of 10</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, '10');
@@ -25,8 +26,8 @@ export default test({
 
 		const button = target.querySelector('button');
 		ok(button);
-		await button.dispatchEvent(new window.Event('click', { bubbles: true }));
-		await Promise.resolve();
+		button.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.equal(input.value, '20');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-range/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-range/_config.js
index d7aa15433f..9c3eecf370 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-range/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-range/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>number 42</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, '42');
@@ -23,7 +24,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = '43';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(component.count, 43);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-deconflicted/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-deconflicted/_config.js
index 4917e8427e..45403898ae 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-deconflicted/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-deconflicted/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<div><input value=x><p>x</p></div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = [...target.querySelectorAll('input')];
 		const event = new window.Event('input');
 
@@ -23,9 +24,10 @@ export default test({
 
 		inputs[0].value = 'b';
 		inputs[1].value = 'y';
-		await inputs[0].dispatchEvent(event);
-		await inputs[1].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[0].dispatchEvent(event);
+		flushSync();
+		inputs[1].dispatchEvent(event);
+		flushSync();
 
 		assert.equal(component.foo, 'b');
 		assert.equal(component.items[0], 'y');
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-reactive/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-reactive/_config.js
index d8fd4c72f3..d20e4a1e88 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-reactive/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual-reactive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -45,7 +46,7 @@ export default test({
 		<p>remaining:one / done:two / remaining:three</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		/**
 		 * @param {number} i
 		 * @param {string} text
@@ -88,8 +89,8 @@ export default test({
 		`
 		);
 
-		await set_text(1, 'four');
-		await Promise.resolve();
+		set_text(1, 'four');
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -113,8 +114,8 @@ export default test({
 			{ done: false, text: 'four' }
 		]);
 
-		await set_done(0, true);
-		await Promise.resolve();
+		set_done(0, true);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual/_config.js
index 088691854e..9922ce1c78 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-contextual/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -29,7 +30,7 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = [...target.querySelectorAll('input')];
 		const items = component.items;
 		const event = new window.Event('input');
@@ -37,8 +38,8 @@ export default test({
 		assert.equal(inputs[0].value, 'one');
 
 		inputs[1].value = 'four';
-		await inputs[1].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[1].dispatchEvent(event);
+		flushSync();
 
 		assert.equal(items[1], 'four');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deconflicted/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deconflicted/_config.js
index ea05ae8e1e..43e0eec907 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deconflicted/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deconflicted/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<input value=world>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, 'world');
@@ -23,7 +24,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = 'everybody';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(input.value, 'everybody');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed-dynamic/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed-dynamic/_config.js
index eab5776eb0..77089cd01d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed-dynamic/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed-dynamic/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -18,7 +19,7 @@ export default test({
 		<pre>{"foo":"a","bar":"b","baz":"c"}</pre>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		const event = new window.Event('input');
@@ -27,7 +28,8 @@ export default test({
 
 		// edit bar
 		input.value = 'e';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -42,7 +44,8 @@ export default test({
 		assert.equal(input.value, 'c');
 
 		input.value = 'f';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -57,7 +60,8 @@ export default test({
 		assert.equal(input.value, 'a');
 
 		input.value = 'd';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed/_config.js
index 039ddcba69..188b3360b5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-computed/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>hello alice</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
@@ -24,7 +25,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = 'bob';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual-computed-dynamic/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual-computed-dynamic/_config.js
index 548fd8f4e4..51e4e12f5f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual-computed-dynamic/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual-computed-dynamic/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -18,7 +19,7 @@ export default test({
 		<pre>{"foo":"a","bar":"b","baz":"c"}</pre>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		const event = new window.Event('input');
@@ -27,8 +28,8 @@ export default test({
 
 		// edit bar
 		input.value = 'e';
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -43,8 +44,8 @@ export default test({
 		assert.equal(input.value, 'c');
 
 		input.value = 'f';
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -59,8 +60,8 @@ export default test({
 		assert.equal(input.value, 'a');
 
 		input.value = 'd';
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual/_config.js
index dc486ec9ba..fad359625a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep-contextual/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -19,16 +20,16 @@ export default test({
 		<div><input value=three><p>three</p></div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = [...target.querySelectorAll('input')];
 
 		assert.equal(inputs[0].value, 'one');
 
-		const event = new window.Event('input');
+		const event = new window.Event('input', { bubbles: true });
 
 		inputs[1].value = 'four';
-		await inputs[1].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[1].dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep/_config.js
index 8a8a2aba6b..8a4dfc0f78 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text-deep/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>hello alice</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
@@ -24,7 +25,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = 'bob';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-input-text/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-input-text/_config.js
index 8720cfb409..f59b6d4f1c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-input-text/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-input-text/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>hello world</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, 'world');
@@ -23,7 +24,8 @@ export default test({
 		const event = new window.Event('input');
 
 		input.value = 'everybody';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-select-implicit-option-value/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-select-implicit-option-value/_config.js
index 2babb062f2..1fea6c08f4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-select-implicit-option-value/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-select-implicit-option-value/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>foo: 2</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const select = target.querySelector('select');
 		ok(select);
 		const options = [...target.querySelectorAll('option')];
@@ -26,7 +27,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[2].selected = true;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.equal(component.foo, 3);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-select-multiple/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-select-multiple/_config.js
index c2d18ae661..42c0e018e5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-select-multiple/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-select-multiple/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>selected: two, three</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const select = target.querySelector('select');
 		ok(select);
 		const options = [...target.querySelectorAll('option')];
@@ -23,7 +24,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[1].selected = false;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.deepEqual(component.selected, ['three']);
 		assert.htmlEqual(
@@ -40,7 +42,8 @@ export default test({
 		);
 
 		options[0].selected = true;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.deepEqual(component.selected, ['one', 'three']);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-select-optgroup/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-select-optgroup/_config.js
index 71c8152398..d9544b7c4d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-select-optgroup/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-select-optgroup/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -23,7 +24,7 @@ export default test({
 		</select>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const select = target.querySelector('select');
 		ok(select);
 
@@ -35,7 +36,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[1].selected = true;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.equal(component.name, 'World');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-select/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-select/_config.js
index 8d467d45b4..5577ec2393 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-select/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-select/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -17,7 +18,7 @@ export default test({
 		return { selected: 'one' };
 	},
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const select = target.querySelector('select');
 		ok(select);
 
@@ -29,7 +30,8 @@ export default test({
 		const change = new window.Event('change');
 
 		options[1].selected = true;
-		await select.dispatchEvent(change);
+		select.dispatchEvent(change);
+		flushSync();
 
 		assert.equal(component.selected, 'two');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-store-deep/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-store-deep/_config.js
index 1de88c4a6c..4854d6dec6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-store-deep/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-store-deep/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,7 +12,7 @@ export default test({
 		<p>hello world</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
@@ -30,7 +31,8 @@ export default test({
 		});
 
 		input.value = 'everybody';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -40,7 +42,8 @@ export default test({
 		`
 		);
 
-		await component.user.set({ name: 'goodbye' });
+		component.user.set({ name: 'goodbye' });
+		flushSync();
 		assert.equal(input.value, 'goodbye');
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-store-each/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-store-each/_config.js
index 80f7b58975..d2df354ea6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-store-each/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-store-each/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -9,12 +10,13 @@ export default test({
 		0
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.checked = true;
-		await input.dispatchEvent(new window.Event('change', { bubbles: true }));
+		input.dispatchEvent(new window.Event('change', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-store/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-store/_config.js
index b8c4ab1f9a..a8ab343002 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-store/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-store/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<div contenteditable="true">world</div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		assert.equal(input.value, 'world');
@@ -31,7 +32,8 @@ export default test({
 		});
 
 		input.value = 'everybody';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -43,7 +45,8 @@ export default test({
 		`
 		);
 
-		await component.name.set('goodbye');
+		component.name.set('goodbye');
+		flushSync();
 		assert.equal(input.value, 'goodbye');
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-textarea/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-textarea/_config.js
index 96536883e5..7b8525279f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-textarea/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-textarea/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		<p>some text</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const textarea = target.querySelector('textarea');
 		ok(textarea);
 		assert.equal(textarea.value, 'some text');
@@ -23,7 +24,8 @@ export default test({
 		const event = new window.Event('input');
 
 		textarea.value = 'hello';
-		await textarea.dispatchEvent(event);
+		textarea.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-this-and-value/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-this-and-value/_config.js
index 18b2bc9089..6bffe1b469 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-this-and-value/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-this-and-value/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,13 +12,14 @@ export default test({
 		<p>value: initial</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 		const event = new window.Event('input');
 
 		input.value = 'changed';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/binding-using-props/_config.js b/packages/svelte/tests/runtime-legacy/samples/binding-using-props/_config.js
index 672932653c..1134b20d0c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/binding-using-props/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/binding-using-props/_config.js
@@ -1,13 +1,15 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		const event = new window.Event('input');
 		input.value = 'changed';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-if/_config.js b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-if/_config.js
index c3fd125ea9..d6e04b8fa4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-if/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-if/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,7 +11,8 @@ export default test({
 
 	async test({ assert, target, window }) {
 		const button = target.querySelector('button');
-		await button?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		button?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-3/_config.js b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-3/_config.js
index 9303a84511..c2f0e69ef5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-3/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-3/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,10 +8,11 @@ export default test({
 		<button></button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		// change from inside
 		const button = target.querySelector('button');
-		await button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-4/_config.js b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-4/_config.js
index 8fc86cd826..51e9d53ef0 100644
--- a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-4/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-4/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,10 +9,11 @@ export default test({
 		<button></button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		// change from inside
 		const button = target.querySelector('button');
-		await button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-5/_config.js b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-5/_config.js
index ebec5b2ae9..768af95193 100644
--- a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-5/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-5/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,10 +11,11 @@ export default test({
 		<button></button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		// change from inside
 		const button = target.querySelector('button');
-		await button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-6/_config.js b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-6/_config.js
index 33e55863ae..a905589f52 100644
--- a/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-6/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/bitmask-overflow-slot-6/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // overflow bitmask + slot missing `let:`
@@ -9,10 +10,11 @@ export default test({
 		<button>Toggle outside</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelectorAll('button')[1];
 		const div = target.querySelector('div');
-		await div?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		div?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -24,7 +26,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-accessors/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-accessors/_config.js
index 827c19ba3a..1a6c9039a7 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-accessors/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-accessors/_config.js
@@ -1,20 +1,23 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [input1, input2] = target.querySelectorAll('input');
 		assert.equal(input1.value, 'something');
 		assert.equal(input2.value, 'something');
 
 		input1.value = 'abc';
 
-		await input1.dispatchEvent(new window.Event('input'));
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 		assert.equal(input1.value, 'abc');
 		assert.equal(input2.value, 'abc');
 
-		await target
+		target
 			.querySelector('button')
 			?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.equal(input1.value, 'Reset');
 		assert.equal(input2.value, 'Reset');
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-d/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-d/_config.js
index 54ce1a678f..aafce86336 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-d/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-d/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,11 +10,11 @@ export default test({
 		<p></p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelectorAll('button')[1];
 
-		await button.dispatchEvent(new window.Event('click', { bubbles: true }));
-		await Promise.resolve();
+		button.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-e/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-e/_config.js
index 3867ef6a5e..1d5ead8b72 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-e/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-e/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,11 +10,11 @@ export default test({
 		<p></p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelectorAll('button')[1];
 
-		await button.dispatchEvent(new window.Event('click', { bubbles: true }));
-		await Promise.resolve();
+		button.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-f/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-f/_config.js
index fd82716f4a..82a6dcefea 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-f/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-blowback-f/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -17,15 +18,11 @@ export default test({
 		<p></p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelectorAll('button')[1];
 
-		await button.dispatchEvent(new window.Event('click', { bubbles: true }));
-		// Multiple ticks necessary because each update is async
-		await Promise.resolve();
-		await Promise.resolve();
-		await Promise.resolve();
-		await Promise.resolve();
+		button.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-deep/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-deep/_config.js
index 0479b7c529..a8881cb1ed 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-deep/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-deep/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,14 +12,14 @@ export default test({
 		<p>foo</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const event = new window.MouseEvent('input');
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'blah';
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.deepEqual(component.deep, { name: 'blah' });
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-deep2/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-deep2/_config.js
index 0479b7c529..a8881cb1ed 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-deep2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-deep2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,14 +12,14 @@ export default test({
 		<p>foo</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const event = new window.MouseEvent('input');
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'blah';
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.deepEqual(component.deep, { name: 'blah' });
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-each-nested/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-each-nested/_config.js
index 6b8c50a023..1826f96913 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-each-nested/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-each-nested/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -13,13 +14,13 @@ export default test({
 		<p>foo, bar, baz</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const event = new window.MouseEvent('input');
 		const inputs = target.querySelectorAll('input');
 
 		inputs[0].value = 'blah';
-		await inputs[0].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.deepEqual(component.a, [{ name: 'blah' }, { name: 'bar' }, { name: 'baz' }]);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-each/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-each/_config.js
index 8c8fad3748..5242488d1f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-each/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-each/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -13,13 +14,13 @@ export default test({
 		<p>foo, bar, baz</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const event = new window.MouseEvent('input');
 		const inputs = target.querySelectorAll('input');
 
 		inputs[0].value = 'blah';
-		await inputs[0].dispatchEvent(event);
-		await Promise.resolve();
+		inputs[0].dispatchEvent(event);
+		flushSync();
 
 		assert.deepEqual(component.a, ['blah', 'bar', 'baz']);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-infinite-loop/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-infinite-loop/_config.js
index 57b3388ab4..e7759ccc87 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-infinite-loop/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-infinite-loop/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -28,12 +29,12 @@ export default test({
 		<p><span>1</span></p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		const spans = target.querySelectorAll('span');
 
-		await spans[0].dispatchEvent(click);
-		await Promise.resolve();
+		spans[0].dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.currentIdentifier, 1);
 		assert.htmlEqual(
@@ -65,8 +66,8 @@ export default test({
 		`
 		);
 
-		await spans[0].dispatchEvent(click);
-		await Promise.resolve();
+		spans[0].dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.currentIdentifier, null);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-nested/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-nested/_config.js
index e81c2580f6..630ddef5dc 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-nested/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-nested/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,11 +16,12 @@ export default test({
 		<p>baz x: initial</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		const buttons = [...target.querySelectorAll('button')];
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 'p');
 		assert.htmlEqual(
@@ -35,7 +37,8 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 'q');
 		assert.htmlEqual(
@@ -51,7 +54,8 @@ export default test({
 		`
 		);
 
-		await buttons[2].dispatchEvent(click);
+		buttons[2].dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 'r');
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-non-leaky/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-non-leaky/_config.js
index da9c55eb1a..4a079d6fc6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-non-leaky/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-non-leaky/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,7 +12,8 @@ export default test({
 		const button = target.querySelector('button');
 		ok(button);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, undefined);
 		assert.htmlEqual(
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, undefined);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-parent-supercedes-child/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-parent-supercedes-child/_config.js
index b63198d2bc..fa20032eb0 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-parent-supercedes-child/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-parent-supercedes-child/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,12 +7,13 @@ export default test({
 		<p>count: 10</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		const button = target.querySelector('button');
 		ok(button);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 11);
 		assert.htmlEqual(
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 12);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-reactive-statement/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-reactive-statement/_config.js
index fa9fe3f3f4..dbd8a5d1a5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-reactive-statement/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-reactive-statement/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,12 +7,13 @@ export default test({
 		<button>button 0</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const event = new window.MouseEvent('click', { bubbles: true });
 
 		const buttons = target.querySelectorAll('button');
 
-		await buttons[0].dispatchEvent(event);
+		buttons[0].dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -20,7 +22,8 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(event);
+		buttons[1].dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -30,7 +33,8 @@ export default test({
 		);
 
 		// reactive update, reset to 2
-		await buttons[0].dispatchEvent(event);
+		buttons[0].dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -40,7 +44,8 @@ export default test({
 		);
 
 		// bound to main, reset to 2
-		await buttons[1].dispatchEvent(event);
+		buttons[1].dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-self-destroying/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-self-destroying/_config.js
index afea1a59f8..fcd468dc9d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-self-destroying/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-self-destroying/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,10 +10,11 @@ export default test({
 		<button>Hide</button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await target.querySelector('button')?.dispatchEvent(click);
+		target.querySelector('button')?.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.show, false);
 		assert.htmlEqual(
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await target.querySelector('button')?.dispatchEvent(click);
+		target.querySelector('button')?.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.show, true);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding-store/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding-store/_config.js
index c41af3ea56..dfa86868ff 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding-store/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding-store/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -12,7 +13,7 @@ export default test({
 		<div></div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		let count = 0;
 		component.callback = () => {
 			count++;
@@ -21,8 +22,8 @@ export default test({
 		const [input1, input2] = target.querySelectorAll('input');
 
 		input1.value = '1';
-		await input1.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -37,8 +38,8 @@ export default test({
 		assert.equal(count, 1);
 
 		input2.value = '123';
-		await input2.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input2.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -53,8 +54,8 @@ export default test({
 		assert.equal(count, 2);
 
 		input1.value = '456';
-		await input1.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-binding/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-binding/_config.js
index 07a3441f4c..40eacb5a5d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-binding/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-binding/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,12 +7,13 @@ export default test({
 		<p>count: 0</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		const button = target.querySelector('button');
 		ok(button);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 1);
 		assert.htmlEqual(
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 2);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-prop-object/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-prop-object/_config.js
index d37a72a2ee..96815e80f8 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-prop-object/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-prop-object/_config.js
@@ -1,10 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `child: 0 parent: 0 <button>inc x</button>`,
 
-	async test({ assert, target }) {
-		await target.querySelector('button')?.click();
+	test({ assert, target }) {
+		target.querySelector('button')?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `child: 1 parent: 1 <button>inc x</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-attribute-order/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-attribute-order/_config.js
index 3e85f77b80..a79720ea3e 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-attribute-order/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-attribute-order/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button slot="footer">Button</button>
 		<button slot="footer">Button</button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [btn, btn1, btn2] = target.querySelectorAll('button');
 
-		await btn.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		btn.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.equal(btn1.disabled, true);
 		assert.equal(btn2.disabled, true);
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-2/_config.js
index ca5dda00f9..cdc011af82 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-2/_config.js
@@ -1,19 +1,22 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: '<input> <input> <input>',
 	ssrHtml: '<input value="Blub"> <input value="Blub"> <input value="Blub">',
 
-	async test({ assert, target, component, window }) {
+	test({ assert, target, component, window }) {
 		const [input1, input2, inputFallback] = target.querySelectorAll('input');
 
 		// TODO this works differently now, deduplicates to one subscription - ok?
 		// assert.equal(component.getSubscriberCount(), 3);
 
 		input1.value = 'a';
-		await input1.dispatchEvent(new window.Event('input'));
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 		input1.value = 'ab';
-		await input1.dispatchEvent(new window.Event('input'));
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 		assert.equal(input1.value, 'ab');
 		assert.equal(input2.value, 'ab');
 		assert.equal(inputFallback.value, 'ab');
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-5/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-5/_config.js
index dc80693d7f..cd1f446d0c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-5/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-5/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,13 +7,14 @@ export default test({
 	<div>Icon B</div>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		ok(btn);
 
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
 
-		await btn.dispatchEvent(clickEvent);
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -22,7 +24,8 @@ export default test({
 			`
 		);
 
-		await btn.dispatchEvent(clickEvent);
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-6/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-6/_config.js
index aa1792ebb3..fac8e94fe9 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-6/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-fallback-6/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 // $$props reactivity in slot fallback
@@ -11,12 +12,13 @@ export default test({
 		{"value":""}
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'abc';
-		await input.dispatchEvent(new window.Event('input'));
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-b/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-b/_config.js
index 993dabf2dc..bb699d4a9f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-b/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-b/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<span>0</span>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-c/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-c/_config.js
index 9a10e0577c..51f2b473f4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-c/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-c/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<span>0 ()</span>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-d/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-d/_config.js
index 49de834cb1..47e917d43a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-d/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-d/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,11 +8,12 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const div = target.querySelector('div');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await div?.dispatchEvent(click);
+		div?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-destructured-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-destructured-2/_config.js
index 31d8a72d2b..e89458160f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-destructured-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-destructured-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,11 +16,12 @@ export default test({
 			<button>Increment</button>
 		</div>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [button1, button2, button3] = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button1.dispatchEvent(event);
+		button1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -38,7 +40,8 @@ export default test({
 		`
 		);
 
-		await button2.dispatchEvent(event);
+		button2.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -57,7 +60,8 @@ export default test({
 		`
 		);
 
-		await button3.dispatchEvent(event);
+		button3.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-scope-3/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-scope-3/_config.js
index 5ebd0ac13a..44a820edc8 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-let-scope-3/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-let-scope-3/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -10,11 +11,12 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
-		await button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-slot-nested-if/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-slot-nested-if/_config.js
index 35b109f811..2ea0504dda 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-slot-nested-if/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-slot-nested-if/_config.js
@@ -1,15 +1,17 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
 	html: `
     <input>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'a';
-		await input.dispatchEvent(new window.Event('input'));
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -20,7 +22,8 @@ export default test({
 		);
 
 		input.value = 'abc';
-		await input.dispatchEvent(new window.Event('input'));
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-b/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-b/_config.js
index 993dabf2dc..bb699d4a9f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-b/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-b/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<span>0</span>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-c/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-c/_config.js
index 9a10e0577c..51f2b473f4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-c/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-c/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<span>0 ()</span>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-d/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-d/_config.js
index 49de834cb1..47e917d43a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-d/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-d/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,11 +8,12 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const div = target.querySelector('div');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await div?.dispatchEvent(click);
+		div?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-destructured-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-destructured-2/_config.js
index 31d8a72d2b..e89458160f 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-destructured-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-svelte-fragment-let-destructured-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,11 +16,12 @@ export default test({
 			<button>Increment</button>
 		</div>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [button1, button2, button3] = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button1.dispatchEvent(event);
+		button1.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -38,7 +40,8 @@ export default test({
 		`
 		);
 
-		await button2.dispatchEvent(event);
+		button2.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -57,7 +60,8 @@ export default test({
 		`
 		);
 
-		await button3.dispatchEvent(event);
+		button3.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-template-inline-mutation/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-template-inline-mutation/_config.js
index aa403357b4..1920fe6575 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-template-inline-mutation/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-template-inline-mutation/_config.js
@@ -1,15 +1,17 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btns = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await btns[0].dispatchEvent(event);
-		await btns[0].dispatchEvent(event);
-		await btns[1].dispatchEvent(event);
-		await btns[1].dispatchEvent(event);
-		await btns[1].dispatchEvent(event);
+		btns[0].dispatchEvent(event);
+		btns[0].dispatchEvent(event);
+		btns[1].dispatchEvent(event);
+		btns[1].dispatchEvent(event);
+		btns[1].dispatchEvent(event);
+		flushSync();
 
 		assert.equal(btns[1].innerHTML, '3');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/component-yield-placement/_config.js b/packages/svelte/tests/runtime-legacy/samples/component-yield-placement/_config.js
index d9505d48c8..be64151449 100644
--- a/packages/svelte/tests/runtime-legacy/samples/component-yield-placement/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/component-yield-placement/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -14,11 +15,12 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/const-tag-invalidate/_config.js b/packages/svelte/tests/runtime-legacy/samples/const-tag-invalidate/_config.js
index 331d1f622b..9c7a4a320d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/const-tag-invalidate/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/const-tag-invalidate/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,11 @@ export default test({
 		<div>[N] B <button>Toggle</button></div>
 		<div>[N] C <button>Toggle</button></div>
 	`,
-	async test({ target, assert, window }) {
+	test({ target, assert, window }) {
 		const [btn1, btn2, btn3] = target.querySelectorAll('button');
-		await btn1.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
-		await btn2.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
-		await Promise.resolve();
+		btn1.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		btn2.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -21,8 +22,8 @@ export default test({
 		`
 		);
 
-		await btn2.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
-		await Promise.resolve();
+		btn2.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -33,8 +34,8 @@ export default test({
 		`
 		);
 
-		await btn3.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
-		await Promise.resolve();
+		btn3.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/context-api/_config.js b/packages/svelte/tests/runtime-legacy/samples/context-api/_config.js
index 7f7290ba91..f02c0a4432 100644
--- a/packages/svelte/tests/runtime-legacy/samples/context-api/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/context-api/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,11 +16,12 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		let buttons = target.querySelectorAll('button');
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -54,7 +56,8 @@ export default test({
 
 		buttons = target.querySelectorAll('button');
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/custom-method/_config.js b/packages/svelte/tests/runtime-legacy/samples/custom-method/_config.js
index 4338b2a59f..3d85874654 100644
--- a/packages/svelte/tests/runtime-legacy/samples/custom-method/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/custom-method/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,13 +7,14 @@ export default test({
 		<p>0</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.equal(component.counter, 1);
 		assert.htmlEqual(
 			target.innerHTML,
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.equal(component.counter, 2);
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/destructuring-one-value-reactive/_config.js b/packages/svelte/tests/runtime-legacy/samples/destructuring-one-value-reactive/_config.js
index 299fa14e2b..eb885e4d48 100644
--- a/packages/svelte/tests/runtime-legacy/samples/destructuring-one-value-reactive/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/destructuring-one-value-reactive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -5,9 +6,10 @@ export default test({
 	<button>false</button>
 	<button>click handler marks foo as reactive</button>
 `,
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/dynamic-component-evals-props-once/_config.js b/packages/svelte/tests/runtime-legacy/samples/dynamic-component-evals-props-once/_config.js
index eb02214ae8..ff3f22ac61 100644
--- a/packages/svelte/tests/runtime-legacy/samples/dynamic-component-evals-props-once/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/dynamic-component-evals-props-once/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,7 +10,8 @@ export default test({
 	async test({ assert, component, window, target }) {
 		const button = target.querySelector('button');
 		// @ts-ignore
-		await button.dispatchEvent(new window.Event('click'));
+		button.dispatchEvent(new window.Event('click'));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -19,7 +21,8 @@ export default test({
 		);
 		assert.equal(component.n, 2);
 		// @ts-ignore
-		await button.dispatchEvent(new window.Event('click'));
+		button.dispatchEvent(new window.Event('click'));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/dynamic-component-spread-props/_config.js b/packages/svelte/tests/runtime-legacy/samples/dynamic-component-spread-props/_config.js
index 8e224b3eb3..643066abb5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/dynamic-component-spread-props/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/dynamic-component-spread-props/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,10 +9,11 @@ export default test({
 		<button>Toggle Component</button>
 	`,
 
-	async test({ assert, window, target }) {
+	test({ assert, window, target }) {
 		const button = target.querySelector('button');
 		// @ts-ignore
-		await button.dispatchEvent(new window.Event('click'));
+		button.dispatchEvent(new window.Event('click'));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -22,7 +24,8 @@ export default test({
 			`
 		);
 		// @ts-ignore
-		await button.dispatchEvent(new window.Event('click'));
+		button.dispatchEvent(new window.Event('click'));
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-binding/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-binding/_config.js
index 377a3503d8..18bd70b9ac 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-binding/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-destructured-object-binding/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -19,12 +20,12 @@ export default test({
 		<p>Doctor Who</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const inputs = target.querySelectorAll('input');
 
 		inputs[1].value = 'Oz';
-		await inputs[1].dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		inputs[1].dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		const { people } = component;
 
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-bind-group/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-bind-group/_config.js
index 5df9a03e8b..e993f73963 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-bind-group/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-bind-group/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,13 +10,13 @@ export default test({
 		<label><input type="checkbox" value="Coconut"> Coconut</label>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [input1, input2, input3, input4, input5] = target.querySelectorAll('input');
 		const event = new window.Event('change');
 
 		input3.checked = true;
-		await input3.dispatchEvent(event);
-		await Promise.resolve();
+		input3.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -35,8 +36,8 @@ export default test({
 		assert.equal(input5.checked, false);
 
 		input4.checked = true;
-		await input4.dispatchEvent(event);
-		await Promise.resolve();
+		input4.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -56,8 +57,8 @@ export default test({
 		assert.equal(input5.checked, false);
 
 		input3.checked = false;
-		await input3.dispatchEvent(event);
-		await Promise.resolve();
+		input3.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-dynamic-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-dynamic-2/_config.js
index 846351c092..a19d789c78 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-dynamic-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-dynamic-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -7,12 +8,13 @@ export default test({
 	<ul></ul>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-index-in-event-handler/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-index-in-event-handler/_config.js
index a1fc90ff50..997ca61ecf 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-index-in-event-handler/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-keyed-index-in-event-handler/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,11 +8,12 @@ export default test({
 		<button>remove</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await target.querySelectorAll('button')[1].dispatchEvent(click);
-		await target.querySelectorAll('button')[1].dispatchEvent(click);
+		target.querySelectorAll('button')[1].dispatchEvent(click);
+		target.querySelectorAll('button')[1].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-2/_config.js
index 940f0308ef..d362c4b6d1 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -9,13 +10,13 @@ export default test({
 		Hello
 		<input value="Hello"/>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'abcd';
-		await input.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-3/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-3/_config.js
index 538dcee572..6c096f7581 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-3/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-3/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -26,11 +27,11 @@ export default test({
 			<input value="App"/>
 		</div>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [input1, input2, input3, input4] = target.querySelectorAll('input');
 		input1.value = 'Awesome';
-		await input1.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input1.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -49,8 +50,8 @@ export default test({
 		);
 
 		input2.value = 'Svelte';
-		await input2.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input2.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -69,8 +70,8 @@ export default test({
 		);
 
 		input3.value = 'Foo';
-		await input3.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input3.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -89,8 +90,8 @@ export default test({
 		);
 
 		input4.value = 'Bar';
-		await input4.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input4.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-4/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-4/_config.js
index 53a88a1880..54c71f80ac 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-4/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind-4/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -15,7 +16,7 @@ export default test({
 		</div>
 		<button>Button</button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
@@ -23,8 +24,8 @@ export default test({
 		ok(button);
 
 		input.value = 'Awesome';
-		await input.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -37,8 +38,8 @@ export default test({
       `
 		);
 
-		await button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
-		await Promise.resolve();
+		button.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -54,8 +55,8 @@ export default test({
 		assert.equal(input.value, 'World');
 
 		input.value = 'Svelte';
-		await input.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind/_config.js
index 940f0308ef..d362c4b6d1 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-block-scope-shadow-bind/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -9,13 +10,13 @@ export default test({
 		Hello
 		<input value="Hello"/>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'abcd';
-		await input.dispatchEvent(new window.Event('input'));
-		await Promise.resolve();
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment-2/_config.js
index f8f36034ea..ed7ecbf927 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -5,12 +6,12 @@ export default test({
 		<span class="content">foo</span>
 		<button>Test</button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
-		await button?.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		button?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment/_config.js b/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment/_config.js
index ac53742f19..c4aa3fb891 100644
--- a/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/each-blocks-assignment/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,12 +11,12 @@ export default test({
 	<span class="content">3</span>
 	<button>Test</button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		let [incrementBtn, ...buttons] = target.querySelectorAll('button');
 
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
-		await buttons[0].dispatchEvent(clickEvent);
-		await Promise.resolve();
+		buttons[0].dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -30,8 +31,8 @@ export default test({
 		`
 		);
 
-		await buttons[0].dispatchEvent(clickEvent);
-		await Promise.resolve();
+		buttons[0].dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -46,9 +47,10 @@ export default test({
 		`
 		);
 
-		await buttons[2].dispatchEvent(clickEvent);
-		await buttons[2].dispatchEvent(clickEvent);
-		await Promise.resolve();
+		buttons[2].dispatchEvent(clickEvent);
+		flushSync();
+		buttons[2].dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -63,8 +65,8 @@ export default test({
 		`
 		);
 
-		await incrementBtn.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		incrementBtn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -83,8 +85,8 @@ export default test({
 
 		[incrementBtn, ...buttons] = target.querySelectorAll('button');
 
-		await buttons[3].dispatchEvent(clickEvent);
-		await Promise.resolve();
+		buttons[3].dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/empty-component-destroy/_config.js b/packages/svelte/tests/runtime-legacy/samples/empty-component-destroy/_config.js
index d6f1b5a07e..f49b9fdde5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/empty-component-destroy/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/empty-component-destroy/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -5,12 +6,14 @@ export default test({
 	  <button>destroy component</button>
 	`,
 
-	async test({ assert, target, window, logs }) {
+	test({ assert, target, window, logs }) {
 		const button = target.querySelector('button');
 		const event = new window.MouseEvent('click');
 
 		// @ts-ignore
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-destructured/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-destructured/_config.js
index 92f4245ca8..35e9c6752c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-destructured/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-destructured/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -5,13 +6,14 @@ export default test({
 		<button>clicked: false</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-2/_config.js
index e48a99997c..681fa25d7b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -8,29 +9,37 @@ export default test({
 		<button>handler_b</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [toggle, handler_a, handler_b] = target.querySelectorAll('button');
 		const p = target.querySelector('p');
 		ok(p);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await handler_a.dispatchEvent(event);
+		handler_a.dispatchEvent(event);
+		flushSync();
 		assert.equal(p.innerHTML, '1');
 
-		await toggle.dispatchEvent(event);
+		toggle.dispatchEvent(event);
+		flushSync();
 
-		await handler_a.dispatchEvent(event);
+		handler_a.dispatchEvent(event);
+		flushSync();
 		assert.equal(p.innerHTML, '2');
 
-		await toggle.dispatchEvent(event);
+		toggle.dispatchEvent(event);
+		flushSync();
 
-		await handler_b.dispatchEvent(event);
+		handler_b.dispatchEvent(event);
+		flushSync();
 		assert.equal(p.innerHTML, '1');
 
-		await toggle.dispatchEvent(event);
+		toggle.dispatchEvent(event);
+		flushSync();
+
+		handler_b.dispatchEvent(event);
+		flushSync();
 
-		await handler_b.dispatchEvent(event);
 		assert.equal(p.innerHTML, '2');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-bound-var/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-bound-var/_config.js
index d245174d9a..afb0fbcc54 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-bound-var/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-bound-var/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -5,13 +6,14 @@ export default test({
 		<button>Click Me</button>
 		Hello World
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-expression/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-expression/_config.js
index e361009847..04d9469ede 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-expression/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-expression/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,13 +9,16 @@ export default test({
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>foo</button>');
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>bar</button>');
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>foo</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-hash/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-hash/_config.js
index 4cb916471c..33710f18ed 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-hash/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic-hash/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,7 +11,7 @@ export default test({
 	<button>click</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [updateButton1, updateButton2, button] = target.querySelectorAll('button');
 
 		const event = new window.MouseEvent('click', { bubbles: true });
@@ -20,7 +21,8 @@ export default test({
 			err = e.message;
 		});
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.equal(err, '', err);
 		assert.htmlEqual(
 			target.innerHTML,
@@ -34,8 +36,10 @@ export default test({
 		`
 		);
 
-		await updateButton1.dispatchEvent(event);
-		await button.dispatchEvent(event);
+		updateButton1.dispatchEvent(event);
+		flushSync();
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -48,8 +52,9 @@ export default test({
 		`
 		);
 
-		await updateButton2.dispatchEvent(event);
-		await button.dispatchEvent(event);
+		updateButton2.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic/_config.js
index 4cb916471c..979ed7a60e 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-dynamic/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,7 +11,7 @@ export default test({
 	<button>click</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [updateButton1, updateButton2, button] = target.querySelectorAll('button');
 
 		const event = new window.MouseEvent('click', { bubbles: true });
@@ -20,7 +21,8 @@ export default test({
 			err = e.message;
 		});
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.equal(err, '', err);
 		assert.htmlEqual(
 			target.innerHTML,
@@ -34,8 +36,9 @@ export default test({
 		`
 		);
 
-		await updateButton1.dispatchEvent(event);
-		await button.dispatchEvent(event);
+		updateButton1.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -48,8 +51,9 @@ export default test({
 		`
 		);
 
-		await updateButton2.dispatchEvent(event);
-		await button.dispatchEvent(event);
+		updateButton2.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-each-context-invalidation/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-each-context-invalidation/_config.js
index 3ffbe42d5a..885422b469 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-each-context-invalidation/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-each-context-invalidation/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,12 +9,13 @@ export default test({
 		<p>on: 1</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(event);
-		await Promise.resolve();
+		buttons[0].dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -24,8 +26,9 @@ export default test({
 		`
 		);
 
-		await buttons[2].dispatchEvent(event);
-		await Promise.resolve();
+		buttons[2].dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-each-deconflicted/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-each-deconflicted/_config.js
index cda08132e6..98433eda04 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-each-deconflicted/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-each-deconflicted/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -11,11 +12,13 @@ export default test({
 		<p>clicked: neither</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(event);
+		buttons[0].dispatchEvent(event);
+		flushSync();
+
 		assert.equal(component.clicked, 'foo');
 		assert.htmlEqual(
 			target.innerHTML,
@@ -26,7 +29,9 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(event);
+		buttons[1].dispatchEvent(event);
+		flushSync();
+
 		assert.equal(component.clicked, 'bar');
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-each/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-each/_config.js
index d638b35a58..aa97c5d24a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-each/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-each/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -15,11 +16,13 @@ export default test({
 		<p>selected: foo</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[1].dispatchEvent(event);
+		buttons[1].dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-modifier-once-duplicated/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-modifier-once-duplicated/_config.js
index ab139e137f..7ab1508673 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-modifier-once-duplicated/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-modifier-once-duplicated/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,14 +12,18 @@ export default test({
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(event);
+		buttons[0].dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`<button>1</button>
 			<button>0</button>`
 		);
 
-		await buttons[1].dispatchEvent(event);
+		buttons[1].dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`<button>1</button>
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler-sanitize/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler-sanitize/_config.js
index 3a030adca4..4986ac9de2 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler-sanitize/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler-sanitize/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -13,7 +14,9 @@ export default test({
 		ok(button);
 		const event = new window.MouseEvent('some-event');
 
-		await div.dispatchEvent(event);
+		div.dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -23,7 +26,9 @@ export default test({
 		`
 		);
 
-		await button.click();
+		button.click();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/event-handler/_config.js b/packages/svelte/tests/runtime-legacy/samples/event-handler/_config.js
index be7a9c7288..0e437cdeb6 100644
--- a/packages/svelte/tests/runtime-legacy/samples/event-handler/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/event-handler/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -5,13 +6,15 @@ export default test({
 		<button>toggle</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -20,7 +23,9 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(event);
+		button.dispatchEvent(event);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/globals-not-overwritten-by-bindings/_config.js b/packages/svelte/tests/runtime-legacy/samples/globals-not-overwritten-by-bindings/_config.js
index 80cb03edb9..6ffb1b7370 100644
--- a/packages/svelte/tests/runtime-legacy/samples/globals-not-overwritten-by-bindings/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/globals-not-overwritten-by-bindings/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -51,14 +52,15 @@ export default test({
 		};
 	},
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const input = /** @type {HTMLInputElement} */ (
 			document.querySelectorAll('input[type="checkbox"]')[2]
 		);
 		const change = new window.Event('change');
 
 		input.checked = true;
-		await input.dispatchEvent(change);
+		input.dispatchEvent(change);
+		flushSync();
 
 		assert.ok(component.todos.third.done);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/if-block-else-update/_config.js b/packages/svelte/tests/runtime-legacy/samples/if-block-else-update/_config.js
index 36b355e945..bed9ff6611 100644
--- a/packages/svelte/tests/runtime-legacy/samples/if-block-else-update/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/if-block-else-update/_config.js
@@ -1,12 +1,15 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
 		const clickEvent = new window.Event('click', { bubbles: true });
 
-		await btn2.dispatchEvent(clickEvent);
+		btn2.dispatchEvent(clickEvent);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -19,7 +22,9 @@ export default test({
 		`
 		);
 
-		await btn1.dispatchEvent(clickEvent);
+		btn1.dispatchEvent(clickEvent);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -32,7 +37,9 @@ export default test({
 		`
 		);
 
-		await btn2.dispatchEvent(clickEvent);
+		btn2.dispatchEvent(clickEvent);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -45,7 +52,9 @@ export default test({
 		`
 		);
 
-		await btn1.dispatchEvent(clickEvent);
+		btn1.dispatchEvent(clickEvent);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/inline-style-become-undefined/_config.js b/packages/svelte/tests/runtime-legacy/samples/inline-style-become-undefined/_config.js
index 59181bb6ce..4e2d400fd5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/inline-style-become-undefined/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/inline-style-become-undefined/_config.js
@@ -1,14 +1,15 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const div = target.querySelector('div');
 		ok(div);
 		const click = new window.MouseEvent('click', { bubbles: true });
 
 		assert.htmlEqual(target.innerHTML, '<div style="background: red;"></div>');
-		await div.dispatchEvent(click);
-		await Promise.resolve();
+		div.dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<div style=""></div>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/inline-style-directive-shorthand-declaration-only/_config.js b/packages/svelte/tests/runtime-legacy/samples/inline-style-directive-shorthand-declaration-only/_config.js
index dfcd5a31fe..b71b056434 100644
--- a/packages/svelte/tests/runtime-legacy/samples/inline-style-directive-shorthand-declaration-only/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/inline-style-directive-shorthand-declaration-only/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,7 +8,7 @@ export default test({
 		<button></button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [p1, p2] = target.querySelectorAll('p');
 
 		assert.equal(window.getComputedStyle(p1).color, 'red');
@@ -16,7 +17,7 @@ export default test({
 		const btn = target.querySelector('button');
 		console.log(btn);
 		btn?.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-destructuring/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-destructuring/_config.js
index e9ec80cf18..4d111c60a8 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-destructuring/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-destructuring/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,11 +9,12 @@ export default test({
 		<p>x: 0</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -23,7 +25,8 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-loop-scope/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-loop-scope/_config.js
index d269944d97..14717a95ec 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-loop-scope/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-loop-scope/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,13 @@ export default test({
 		<p>x: 0</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-multiple-assignments/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-multiple-assignments/_config.js
index 1645d87a77..cd13cc73ac 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-multiple-assignments/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-multiple-assignments/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -11,11 +12,12 @@ export default test({
 		<p>bar: 0</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.foo, 4);
 		assert.equal(component.bar, 2);
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-update/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-update/_config.js
index c18060047b..a7673f2573 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-update/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-script-update/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<p>x: 0</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-destructuring/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-destructuring/_config.js
index e9ec80cf18..b2c0e80831 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-destructuring/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-destructuring/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -12,7 +13,9 @@ export default test({
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -23,7 +26,9 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-loop-scope/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-loop-scope/_config.js
index d269944d97..14717a95ec 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-loop-scope/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-loop-scope/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,13 @@ export default test({
 		<p>x: 0</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-multiple-assignments/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-multiple-assignments/_config.js
index 1645d87a77..cd13cc73ac 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-multiple-assignments/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-multiple-assignments/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -11,11 +12,12 @@ export default test({
 		<p>bar: 0</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.foo, 4);
 		assert.equal(component.bar, 2);
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-update/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-update/_config.js
index c18060047b..a7673f2573 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-update/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-template-update/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<p>x: 0</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/instrumentation-update-expression/_config.js b/packages/svelte/tests/runtime-legacy/samples/instrumentation-update-expression/_config.js
index d58be61a36..a3c5b2a825 100644
--- a/packages/svelte/tests/runtime-legacy/samples/instrumentation-update-expression/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/instrumentation-update-expression/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,24 +10,28 @@ export default test({
 		<button>bar.bar++</button>
 		<button>++bar.bar</button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [foo, bar] = target.querySelectorAll('p');
 		const [button1, button2, button3, button4] = target.querySelectorAll('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
 
-		await button1.dispatchEvent(event);
+		button1.dispatchEvent(event);
+		flushSync();
 		assert.equal(foo.innerHTML, '1');
 		assert.equal(bar.innerHTML, '0');
 
-		await button2.dispatchEvent(event);
+		button2.dispatchEvent(event);
+		flushSync();
 		assert.equal(foo.innerHTML, '2');
 		assert.equal(bar.innerHTML, '0');
 
-		await button3.dispatchEvent(event);
+		button3.dispatchEvent(event);
+		flushSync();
 		assert.equal(foo.innerHTML, '2');
 		assert.equal(bar.innerHTML, '1');
 
-		await button4.dispatchEvent(event);
+		button4.dispatchEvent(event);
+		flushSync();
 		assert.equal(foo.innerHTML, '2');
 		assert.equal(bar.innerHTML, '2');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/invalidation-in-if-condition/_config.js b/packages/svelte/tests/runtime-legacy/samples/invalidation-in-if-condition/_config.js
index 881cba8c13..02f43929d8 100644
--- a/packages/svelte/tests/runtime-legacy/samples/invalidation-in-if-condition/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/invalidation-in-if-condition/_config.js
@@ -1,21 +1,25 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
 	html: '<button>false 0</button>',
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>true 1</button>');
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>false 1</button>');
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>true 2</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/key-block-component-slot/_config.js b/packages/svelte/tests/runtime-legacy/samples/key-block-component-slot/_config.js
index 8265e5b62f..837d1d112b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/key-block-component-slot/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/key-block-component-slot/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /** @type {string[]} */
@@ -13,14 +14,14 @@ export default test({
 		logs = [];
 	},
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		assert.deepEqual(logs, ['mount']);
 
 		const button = target.querySelector('button');
 
 		const click = new window.MouseEvent('click', { bubbles: true });
-		await button?.dispatchEvent(click);
-		await Promise.resolve();
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.deepEqual(logs, ['mount', 'unmount', 'mount']);
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/key-block-static-if/_config.js b/packages/svelte/tests/runtime-legacy/samples/key-block-static-if/_config.js
index 0aa126ddc6..baa6ac3a7e 100644
--- a/packages/svelte/tests/runtime-legacy/samples/key-block-static-if/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/key-block-static-if/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,7 +11,8 @@ export default test({
 	async test({ assert, target, window }) {
 		const button = target.querySelector('button');
 
-		await button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		button?.dispatchEvent(new window.Event('click', { bubbles: true }));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/mutation-tracking-across-sibling-scopes/_config.js b/packages/svelte/tests/runtime-legacy/samples/mutation-tracking-across-sibling-scopes/_config.js
index b67753cffc..fbbc749b6d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/mutation-tracking-across-sibling-scopes/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/mutation-tracking-across-sibling-scopes/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, component, target }) {
+	test({ assert, component, target }) {
 		assert.htmlEqual(component.div.innerHTML, '<div>+</div><div>-</div>');
 
 		const event = new window.Event('change');
@@ -9,8 +10,8 @@ export default test({
 		ok(input);
 
 		input.checked = false;
-		await input.dispatchEvent(event);
-		await Promise.resolve();
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(component.div.innerHTML, '<div>-</div><div>-</div>');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment-2/_config.js b/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment-2/_config.js
index 9e41e8074e..a8451373c4 100644
--- a/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment-2/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -17,10 +18,11 @@ export default test({
 		<button>Click me!</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await button?.dispatchEvent(clickEvent);
+		button?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment/_config.js b/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment/_config.js
index 021f851197..79b68dd931 100644
--- a/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/nested-destructure-assignment/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -17,10 +18,11 @@ export default test({
 		<button>Click me!</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await button?.dispatchEvent(clickEvent);
+		button?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/prop-no-change/_config.js b/packages/svelte/tests/runtime-legacy/samples/prop-no-change/_config.js
index 71720f3528..905c2a6226 100644
--- a/packages/svelte/tests/runtime-legacy/samples/prop-no-change/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/prop-no-change/_config.js
@@ -1,9 +1,11 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, logs, target }) {
+	test({ assert, logs, target }) {
 		assert.deepEqual(logs, ['primitive', 'object']);
-		await target.querySelector('button')?.click();
+		target.querySelector('button')?.click();
+		flushSync();
 		assert.deepEqual(logs, ['primitive', 'object', 'object']);
 	}
 });
diff --git a/packages/svelte/tests/runtime-legacy/samples/props-reactive-slot/_config.js b/packages/svelte/tests/runtime-legacy/samples/props-reactive-slot/_config.js
index b6b3ee3a04..85edf41dae 100644
--- a/packages/svelte/tests/runtime-legacy/samples/props-reactive-slot/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/props-reactive-slot/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,11 +7,12 @@ export default test({
 		<button>Change</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
 
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/props-reassign/_config.js b/packages/svelte/tests/runtime-legacy/samples/props-reassign/_config.js
index d5760f7a77..b9ddd39238 100644
--- a/packages/svelte/tests/runtime-legacy/samples/props-reassign/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/props-reassign/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,10 +8,11 @@ export default test({
 		<button>update</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
-		await btn1.click();
+		btn1.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -21,7 +23,8 @@ export default test({
 		`
 		);
 
-		await btn2.click();
+		btn2.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/raw-mustache-as-root/_config.js b/packages/svelte/tests/runtime-legacy/samples/raw-mustache-as-root/_config.js
index ee75954855..63a4b8aed3 100644
--- a/packages/svelte/tests/runtime-legacy/samples/raw-mustache-as-root/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/raw-mustache-as-root/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,15 +7,14 @@ export default test({
 		<p>Another first line</p>
 		<p>This line should be last.</p>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		ok(btn);
 
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
 
-		await btn.dispatchEvent(clickEvent);
-		await Promise.resolve(); // TODO: We use a pre_effect for $:, changing to computed will make this line redundant
-		await Promise.resolve(); // additional tick to rerender
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -25,9 +25,8 @@ export default test({
 			`
 		);
 
-		await btn.dispatchEvent(clickEvent);
-		await Promise.resolve(); // TODO: We use a pre_effect for $:, changing to computed will make this line redundant
-		await Promise.resolve(); // additional tick to rerender
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/raw-mustache-inside-slot/_config.js b/packages/svelte/tests/runtime-legacy/samples/raw-mustache-inside-slot/_config.js
index a8d9c3e11f..63a4b8aed3 100644
--- a/packages/svelte/tests/runtime-legacy/samples/raw-mustache-inside-slot/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/raw-mustache-inside-slot/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,14 +7,14 @@ export default test({
 		<p>Another first line</p>
 		<p>This line should be last.</p>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		ok(btn);
 
 		const clickEvent = new window.MouseEvent('click', { bubbles: true });
 
-		await btn.dispatchEvent(clickEvent);
-		await Promise.resolve(); // additional tick to rerender
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -24,8 +25,8 @@ export default test({
 			`
 		);
 
-		await btn.dispatchEvent(clickEvent);
-		await Promise.resolve(); // additional tick to rerender
+		btn.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/reactive-compound-operator/_config.js b/packages/svelte/tests/runtime-legacy/samples/reactive-compound-operator/_config.js
index 03e69eac3c..9eecf4a7a5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/reactive-compound-operator/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/reactive-compound-operator/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,7 +12,8 @@ export default test({
 		const button = target.querySelector('button');
 		ok(button);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 2);
 		assert.htmlEqual(
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 6);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/reactive-function-called-reassigned/_config.js b/packages/svelte/tests/runtime-legacy/samples/reactive-function-called-reassigned/_config.js
index ee28fb43c3..dacf6ffbc5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/reactive-function-called-reassigned/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/reactive-function-called-reassigned/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 /** @type {string[]} */
@@ -17,7 +18,7 @@ export default test({
 	before_test() {
 		called = 0;
 	},
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		assert.equal(called, 1);
 
 		const input = target.querySelector('input');
@@ -25,7 +26,8 @@ export default test({
 
 		const event = new window.Event('input');
 		input.value = 'h';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.equal(called, 2);
 		assert.equal(value.length, 3);
diff --git a/packages/svelte/tests/runtime-legacy/samples/reactive-statement-indirect/_config.js b/packages/svelte/tests/runtime-legacy/samples/reactive-statement-indirect/_config.js
index 96fe6ded05..4cc21b0db9 100644
--- a/packages/svelte/tests/runtime-legacy/samples/reactive-statement-indirect/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/reactive-statement-indirect/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -5,12 +6,12 @@ export default test({
 		<h1>2</h1>
 		<button>Increment</button>
 	`,
-	async test({ assert, target }) {
-		await target
+	test({ assert, target }) {
+		target
 			.querySelector('button')
 			?.dispatchEvent(new window.MouseEvent('click', { bubbles: true }));
 
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/reactive-update-expression/_config.js b/packages/svelte/tests/runtime-legacy/samples/reactive-update-expression/_config.js
index 8df0d32e9d..38494fee8a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/reactive-update-expression/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/reactive-update-expression/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -6,14 +7,15 @@ export default test({
 	<p>count: 1</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const click = new window.MouseEvent('click', { bubbles: true });
 		const button = target.querySelector('button');
 		ok(button);
 
 		assert.equal(component.x, 1);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 3);
 		assert.htmlEqual(
@@ -24,7 +26,8 @@ export default test({
 		`
 		);
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.equal(component.x, 5);
 		assert.htmlEqual(
diff --git a/packages/svelte/tests/runtime-legacy/samples/reactive-value-mutate-const/_config.js b/packages/svelte/tests/runtime-legacy/samples/reactive-value-mutate-const/_config.js
index 55f4777c1a..03d973fc0b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/reactive-value-mutate-const/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/reactive-value-mutate-const/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,12 +7,12 @@ export default test({
 		<div>{}</div>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const button = target.querySelector('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button?.dispatchEvent(click);
-		await Promise.resolve();
+		button?.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/rest-props-reassign/_config.js b/packages/svelte/tests/runtime-legacy/samples/rest-props-reassign/_config.js
index 4e8638eab2..694ba871ed 100644
--- a/packages/svelte/tests/runtime-legacy/samples/rest-props-reassign/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/rest-props-reassign/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,10 +8,11 @@ export default test({
 		<button>update</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
-		await btn1.click();
+		btn1.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -21,7 +23,8 @@ export default test({
 		`
 		);
 
-		await btn2.click();
+		btn2.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/rest-props-without-props/_config.js b/packages/svelte/tests/runtime-legacy/samples/rest-props-without-props/_config.js
index ff97265fb5..a210563ec3 100644
--- a/packages/svelte/tests/runtime-legacy/samples/rest-props-without-props/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/rest-props-without-props/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,11 +11,12 @@ export default test({
 		<div d="4" e="5" foo="1"></div>
 		<button></button><button></button><button></button><button></button>
 	`,
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [btn1, btn2, btn3, btn4] = target.querySelectorAll('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
 
-		await btn1.dispatchEvent(clickEvent);
+		btn1.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -26,8 +28,8 @@ export default test({
 		`
 		);
 
-		await btn2.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn2.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -39,8 +41,8 @@ export default test({
 		`
 		);
 
-		await btn3.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn3.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -52,8 +54,8 @@ export default test({
 		`
 		);
 
-		await btn4.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn4.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/rest-props/_config.js b/packages/svelte/tests/runtime-legacy/samples/rest-props/_config.js
index 2ee0a7e2b6..969843b83b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/rest-props/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/rest-props/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -12,11 +13,12 @@ export default test({
 		<button></button><button></button><button></button><button></button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [btn1, btn2, btn3, btn4] = target.querySelectorAll('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
 
-		await btn1.dispatchEvent(clickEvent);
+		btn1.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -29,8 +31,8 @@ export default test({
 		`
 		);
 
-		await btn2.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn2.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -43,8 +45,8 @@ export default test({
 		`
 		);
 
-		await btn3.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn3.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -57,8 +59,8 @@ export default test({
 		`
 		);
 
-		await btn4.dispatchEvent(clickEvent);
-		await Promise.resolve();
+		btn4.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/select-lazy-options/_config.js b/packages/svelte/tests/runtime-legacy/samples/select-lazy-options/_config.js
index 03714f0875..88a8281f44 100644
--- a/packages/svelte/tests/runtime-legacy/samples/select-lazy-options/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/select-lazy-options/_config.js
@@ -1,8 +1,10 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	async test({ assert, target }) {
-		await target.querySelector('button')?.click();
+		target.querySelector('button')?.click();
+		flushSync();
 		await Promise.resolve();
 
 		const options = target.querySelectorAll('option');
diff --git a/packages/svelte/tests/runtime-legacy/samples/spread-component-with-bind/_config.js b/packages/svelte/tests/runtime-legacy/samples/spread-component-with-bind/_config.js
index ade62ee209..3dbf2d3e58 100644
--- a/packages/svelte/tests/runtime-legacy/samples/spread-component-with-bind/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/spread-component-with-bind/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
@@ -11,12 +12,13 @@ export default test({
 		<input value=foo>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		input.value = 'bar';
-		await input.dispatchEvent(new window.Event('input'));
+		input.dispatchEvent(new window.Event('input'));
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/spread-element-input-select-multiple/_config.js b/packages/svelte/tests/runtime-legacy/samples/spread-element-input-select-multiple/_config.js
index 1670bb0c31..cdbf94ace5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/spread-element-input-select-multiple/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/spread-element-input-select-multiple/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const [input1, input2] = target.querySelectorAll('input');
 		const select = target.querySelector('select');
 		ok(select);
@@ -15,7 +16,8 @@ export default test({
 		const event = new window.Event('change');
 
 		input1.checked = false;
-		await input1.dispatchEvent(event);
+		input1.dispatchEvent(event);
+		flushSync();
 
 		selections = Array.from(select.selectedOptions);
 		assert.equal(selections.length, 1);
@@ -23,10 +25,11 @@ export default test({
 		assert.ok(selections.includes(option2));
 
 		input2.checked = false;
-		await input2.dispatchEvent(event);
+		input2.dispatchEvent(event);
+		flushSync();
 		input1.checked = true;
-		await input1.dispatchEvent(event);
-
+		input1.dispatchEvent(event);
+		flushSync();
 		selections = Array.from(select.selectedOptions);
 		assert.equal(selections.length, 1);
 		assert.ok(selections.includes(option1));
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates-property/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates-property/_config.js
index 7e3c3bcc9c..c901a425a5 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates-property/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates-property/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,11 +9,12 @@ export default test({
 		<button></button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await btn1.dispatchEvent(click);
+		btn1.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -24,7 +26,8 @@ export default test({
 		`
 		);
 
-		await btn2.dispatchEvent(click);
+		btn2.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates/_config.js
index 85054029c3..35e0425d3d 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-assignment-updates/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 import { writable } from 'svelte/store';
 
@@ -11,13 +12,14 @@ export default test({
 		<p>doubled: 0</p>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -27,7 +29,8 @@ export default test({
 		`
 		);
 
-		await component.count.set(42);
+		component.count.set(42);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe-implicit/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe-implicit/_config.js
index 65403b047b..a6be345b6b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe-implicit/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe-implicit/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 import { writable } from 'svelte/store';
 
@@ -10,13 +11,14 @@ export default test({
 		<button>count 0</button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -25,7 +27,8 @@ export default test({
 		`
 		);
 
-		await component.count.set(42);
+		component.count.set(42);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe/_config.js
index 65403b047b..a6be345b6b 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-auto-subscribe/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 import { writable } from 'svelte/store';
 
@@ -10,13 +11,14 @@ export default test({
 		<button>count 0</button>
 	`,
 
-	async test({ assert, component, target, window }) {
+	test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
 		ok(button);
 
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await button.dispatchEvent(click);
+		button.dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -25,7 +27,8 @@ export default test({
 		`
 		);
 
-		await component.count.set(42);
+		component.count.set(42);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-deep/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-deep/_config.js
index 672932653c..1134b20d0c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-deep/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-deep/_config.js
@@ -1,13 +1,15 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		const event = new window.Event('input');
 		input.value = 'changed';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-destructuring/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-destructuring/_config.js
index 672932653c..1134b20d0c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-each-binding-destructuring/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-each-binding-destructuring/_config.js
@@ -1,13 +1,15 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		const event = new window.Event('input');
 		input.value = 'changed';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-each-binding/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-each-binding/_config.js
index 672932653c..1134b20d0c 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-each-binding/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-each-binding/_config.js
@@ -1,13 +1,15 @@
+import { flushSync } from 'svelte';
 import { ok, test } from '../../test';
 
 export default test({
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const input = target.querySelector('input');
 		ok(input);
 
 		const event = new window.Event('input');
 		input.value = 'changed';
-		await input.dispatchEvent(event);
+		input.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/store-resubscribe/_config.js b/packages/svelte/tests/runtime-legacy/samples/store-resubscribe/_config.js
index bd2d48a714..5c9229e7cf 100644
--- a/packages/svelte/tests/runtime-legacy/samples/store-resubscribe/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/store-resubscribe/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,11 +8,12 @@ export default test({
 		<button>reset</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click', { bubbles: true });
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -22,7 +24,8 @@ export default test({
 		`
 		);
 
-		await buttons[1].dispatchEvent(click);
+		buttons[1].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
@@ -33,7 +36,8 @@ export default test({
 		`
 		);
 
-		await buttons[0].dispatchEvent(click);
+		buttons[0].dispatchEvent(click);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/transition-js-events-in-out/_config.js b/packages/svelte/tests/runtime-legacy/samples/transition-js-events-in-out/_config.js
index 785f51a4fa..5c4e6ea611 100644
--- a/packages/svelte/tests/runtime-legacy/samples/transition-js-events-in-out/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/transition-js-events-in-out/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -36,6 +37,8 @@ export default test({
 		await raf.tick(100);
 		assert.equal(component.intro_count, 0);
 
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-legacy/samples/transition-js-if-outro-unrelated-component-binding-update/_config.js b/packages/svelte/tests/runtime-legacy/samples/transition-js-if-outro-unrelated-component-binding-update/_config.js
index 63827a1962..ccab0ca834 100644
--- a/packages/svelte/tests/runtime-legacy/samples/transition-js-if-outro-unrelated-component-binding-update/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/transition-js-if-outro-unrelated-component-binding-update/_config.js
@@ -1,10 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, window, raf }) {
+	test({ assert, target, window, raf }) {
 		const button = target.querySelector('button');
 		const event = new window.MouseEvent('click', { bubbles: true });
-		await button?.dispatchEvent(event);
+		button?.dispatchEvent(event);
+		flushSync();
 		raf.tick(500);
 		assert.htmlEqual(target.innerHTML, '');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/window-binding-resize/_config.js b/packages/svelte/tests/runtime-legacy/samples/window-binding-resize/_config.js
index 584fa02d45..62d24e7f1a 100644
--- a/packages/svelte/tests/runtime-legacy/samples/window-binding-resize/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/window-binding-resize/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -22,7 +23,7 @@ export default test({
 
 	mode: ['client', 'hydrate'],
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const event = new window.Event('resize');
 
 		Object.defineProperties(window, {
@@ -40,7 +41,8 @@ export default test({
 			}
 		});
 
-		await window.dispatchEvent(event);
+		window.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/window-binding-scroll-store/_config.js b/packages/svelte/tests/runtime-legacy/samples/window-binding-scroll-store/_config.js
index 3a0f3ccd73..115c3cfd38 100644
--- a/packages/svelte/tests/runtime-legacy/samples/window-binding-scroll-store/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/window-binding-scroll-store/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /** @type {Window['scrollTo']} */
@@ -21,7 +22,7 @@ export default test({
 		window.scrollTo = original_scrollTo;
 	},
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		assert.equal(window.scrollY, 0);
 
 		const event = new window.Event('scroll');
@@ -32,7 +33,8 @@ export default test({
 			}
 		});
 
-		await window.dispatchEvent(event);
+		window.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-legacy/samples/window-event-context/_config.js b/packages/svelte/tests/runtime-legacy/samples/window-event-context/_config.js
index 42b8359059..775ea17bbb 100644
--- a/packages/svelte/tests/runtime-legacy/samples/window-event-context/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/window-event-context/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -12,11 +13,13 @@ export default test({
 	async test({ assert, component, target, window }) {
 		const event = new window.Event('click');
 
-		await window.dispatchEvent(event);
+		window.dispatchEvent(event);
+		flushSync();
 		assert.equal(component.foo, false);
 		assert.htmlEqual(target.innerHTML, 'false');
 
-		await window.dispatchEvent(event);
+		window.dispatchEvent(event);
+		flushSync();
 		assert.equal(component.foo, true);
 		assert.htmlEqual(target.innerHTML, 'true');
 	}
diff --git a/packages/svelte/tests/runtime-legacy/samples/window-event/_config.js b/packages/svelte/tests/runtime-legacy/samples/window-event/_config.js
index e77a1f48b9..ac072aced2 100644
--- a/packages/svelte/tests/runtime-legacy/samples/window-event/_config.js
+++ b/packages/svelte/tests/runtime-legacy/samples/window-event/_config.js
@@ -1,9 +1,10 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: '<div>x</div>',
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const event = new window.Event('resize');
 
 		Object.defineProperties(window, {
@@ -17,8 +18,8 @@ export default test({
 			}
 		});
 
-		await window.dispatchEvent(event);
-		await Promise.resolve();
+		window.dispatchEvent(event);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/ambiguous-source/_config.js b/packages/svelte/tests/runtime-runes/samples/ambiguous-source/_config.js
index 2775015dff..9da297dcaf 100644
--- a/packages/svelte/tests/runtime-runes/samples/ambiguous-source/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/ambiguous-source/_config.js
@@ -1,11 +1,13 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0 / 0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1 / 1</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/attribute-spread-reactivitiy/_config.js b/packages/svelte/tests/runtime-runes/samples/attribute-spread-reactivitiy/_config.js
index 9baec30b4f..77edb47731 100644
--- a/packages/svelte/tests/runtime-runes/samples/attribute-spread-reactivitiy/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/attribute-spread-reactivitiy/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,11 +8,11 @@ export default test({
 		<button>toggle</button
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1] = target.querySelectorAll('button');
 
 		b1?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/bind-state-property/_config.js b/packages/svelte/tests/runtime-runes/samples/bind-state-property/_config.js
index 921fa71980..8cb8fa59d9 100644
--- a/packages/svelte/tests/runtime-runes/samples/bind-state-property/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/bind-state-property/_config.js
@@ -1,12 +1,15 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<input type="checkbox"><br>\nChecked:\nfalse`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const input = target.querySelector('input');
 
-		await input?.click();
+		input?.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<input type="checkbox"><br>\nChecked:\ntrue`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/bindings-form-reset/_config.js b/packages/svelte/tests/runtime-runes/samples/bindings-form-reset/_config.js
index 069d183177..853f6a404a 100644
--- a/packages/svelte/tests/runtime-runes/samples/bindings-form-reset/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/bindings-form-reset/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -10,7 +11,8 @@ export default test({
 		);
 
 		await target.querySelector('button')?.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			p?.innerHTML || '',
 			`{"text":"","checkbox":false,"radio_group":null,"checkbox_group":[],"select":"a","textarea":""}`
diff --git a/packages/svelte/tests/runtime-runes/samples/class-frozen-state-object/_config.js b/packages/svelte/tests/runtime-runes/samples/class-frozen-state-object/_config.js
index 79a0d13bdd..4b043a75e2 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-frozen-state-object/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-frozen-state-object/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>0</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>0</button>`);
 
 		assert.deepEqual(logs, ['read only', 'read only']);
diff --git a/packages/svelte/tests/runtime-runes/samples/class-frozen-state/_config.js b/packages/svelte/tests/runtime-runes/samples/class-frozen-state/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-frozen-state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-frozen-state/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state-object/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state-object/_config.js
index 79a0d13bdd..4b043a75e2 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state-object/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state-object/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>0</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>0</button>`);
 
 		assert.deepEqual(logs, ['read only', 'read only']);
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-frozen-state/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-state-increment/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-state-increment/_config.js
index c7ea1a16db..9f7c3aec9b 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-state-increment/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-state-increment/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>1</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>4</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-state-init/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-state-init/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-state-init/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-state-init/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-state-proxy/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-state-proxy/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-state-proxy/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-state-proxy/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-private-state/_config.js b/packages/svelte/tests/runtime-runes/samples/class-private-state/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-private-state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-private-state/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-deep-update/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-deep-update/_config.js
index e9ef53f95f..27e0579bb2 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-deep-update/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-deep-update/_config.js
@@ -1,15 +1,20 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0 / 0</button><button>0 / 0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
-		await btn1?.click();
+		btn1?.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>1 / 0</button><button>1 / 0</button>`);
 
-		await btn2?.click();
+		btn2?.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>2 / 1</button><button>2 / 1</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-derived-fn/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-derived-fn/_config.js
index 54e9e296fc..141d994a2f 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-derived-fn/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-derived-fn/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<p>doubled: 0</p>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -18,7 +20,8 @@ export default test({
 			`
 		);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-derived-private/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-derived-private/_config.js
index 54e9e296fc..141d994a2f 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-derived-private/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-derived-private/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<p>doubled: 0</p>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -18,7 +20,8 @@ export default test({
 			`
 		);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-derived/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-derived/_config.js
index 54e9e296fc..141d994a2f 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-derived/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-derived/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<p>doubled: 0</p>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -18,7 +20,8 @@ export default test({
 			`
 		);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-increment/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-increment/_config.js
index c7ea1a16db..9f7c3aec9b 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-increment/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-increment/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>1</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>4</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-init-conflict/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-init-conflict/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-init-conflict/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-init-conflict/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-2/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-2/_config.js
index 6d49c0436f..6dd1762e30 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-2/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 
 		assert.deepEqual(logs, [undefined]);
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-3/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-3/_config.js
index 6d49c0436f..6dd1762e30 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-3/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager-3/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 
 		assert.deepEqual(logs, [undefined]);
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager/_config.js
index 4da3fffc5e..cea45924a9 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-init-eager/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-init-eager/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 
 		assert.deepEqual(logs, [100]);
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-init/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-init/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-init/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-init/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-proxy/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-proxy/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-proxy/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-proxy/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-public-private/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-public-private/_config.js
index 7601ea5fd5..db67cb10f5 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-public-private/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-public-private/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,7 +10,9 @@ export default test({
 	async test({ assert, target }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
-		await btn1?.click();
+		btn1?.click();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -18,7 +21,9 @@ export default test({
 			`
 		);
 
-		await btn2?.click();
+		btn2?.click();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state-with-literal/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state-with-literal/_config.js
index 5c9ce546c9..d2252ef0fd 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state-with-literal/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state-with-literal/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>false</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>true</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>false</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/class-state/_config.js b/packages/svelte/tests/runtime-runes/samples/class-state/_config.js
index 436ce99798..8a7fcc66a0 100644
--- a/packages/svelte/tests/runtime-runes/samples/class-state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/class-state/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1</button>`);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/component-let-directive/_config.js b/packages/svelte/tests/runtime-runes/samples/component-let-directive/_config.js
index 386a3831b0..91c5fc418f 100644
--- a/packages/svelte/tests/runtime-runes/samples/component-let-directive/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/component-let-directive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,9 +7,10 @@ export default test({
 		<p slot="named">named slot count is not state</p>
 	`,
 
-	test: async ({ assert, target }) => {
+	test: ({ assert, target }) => {
 		const button = target.querySelector('button');
-		await button?.click();
+		button?.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-direct/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-direct/_config.js
index 09bd0a9aad..2ce8bf7e3f 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-direct/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-direct/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-fn-destructure/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-fn-destructure/_config.js
index 71c7e40ed5..698fce15c4 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-fn-destructure/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-fn-destructure/_config.js
@@ -1,13 +1,15 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	mode: ['server'],
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window, logs }) {
+	test({ assert, target, window, logs }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 		assert.deepEqual(logs, ['create_derived']);
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-fn/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-fn/_config.js
index 09bd0a9aad..2ce8bf7e3f 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-fn/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-fn/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-indirect-arrow-fn/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-indirect-arrow-fn/_config.js
index 09bd0a9aad..e896f69d44 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-indirect-arrow-fn/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-indirect-arrow-fn/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,7 +7,8 @@ export default test({
 	async test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn-2/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn-2/_config.js
index 09bd0a9aad..2ce8bf7e3f 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn-2/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn/_config.js
index 09bd0a9aad..2ce8bf7e3f 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-indirect-fn/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-proxy/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-proxy/_config.js
index 32340d018a..219cea79ea 100644
--- a/packages/svelte/tests/runtime-runes/samples/derived-proxy/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/derived-proxy/_config.js
@@ -1,15 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0 / 0</button><button>0 / 0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [btn1, btn2] = target.querySelectorAll('button');
 
-		await btn1?.click();
+		btn1?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1 / 2</button><button>1 / 2</button>`);
 
-		await btn2?.click();
+		btn2?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>2 / 4</button><button>2 / 4</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/destructure-derived-event/_config.js b/packages/svelte/tests/runtime-runes/samples/destructure-derived-event/_config.js
index 6ad462cddb..187cc4faba 100644
--- a/packages/svelte/tests/runtime-runes/samples/destructure-derived-event/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/destructure-derived-event/_config.js
@@ -1,9 +1,11 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 
 		assert.deepEqual(logs, ['works!']);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/each-mutation/_config.js b/packages/svelte/tests/runtime-runes/samples/each-mutation/_config.js
index 0dac8c623b..81920136d8 100644
--- a/packages/svelte/tests/runtime-runes/samples/each-mutation/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/each-mutation/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,18 +8,18 @@ export default test({
 	<button>FOO</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [btn1, btn2, btn3] = target.querySelectorAll('button');
 
 		// ensure each click runs in its own rerender task
-		await btn1.click();
-		await Promise.resolve();
+		btn1.click();
+		flushSync();
 
-		await btn2.click();
-		await Promise.resolve();
+		btn2.click();
+		flushSync();
 
-		await btn3.click();
-		await Promise.resolve();
+		btn3.click();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/effect/_config.js b/packages/svelte/tests/runtime-runes/samples/effect/_config.js
index 384356dc07..c836a2e593 100644
--- a/packages/svelte/tests/runtime-runes/samples/effect/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/effect/_config.js
@@ -1,11 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const [b1, b2] = target.querySelectorAll('button');
 		b1.click();
 		b2.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.deepEqual(logs, [0, 1]);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/effects-order/_config.js b/packages/svelte/tests/runtime-runes/samples/effects-order/_config.js
index e4ca2d72a6..42d82f4973 100644
--- a/packages/svelte/tests/runtime-runes/samples/effects-order/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/effects-order/_config.js
@@ -1,11 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const [b1, b2] = target.querySelectorAll('button');
 		b1.click();
 		b2.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.deepEqual(logs, ['first0', 'second0', 'first1', 'second1']);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/event-arguments-2/_config.js b/packages/svelte/tests/runtime-runes/samples/event-arguments-2/_config.js
index f2e6c67f8a..4af1ce0070 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-arguments-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-arguments-2/_config.js
@@ -1,13 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1] = target.querySelectorAll('button');
 
 		b1?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>1</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/event-arguments/_config.js b/packages/svelte/tests/runtime-runes/samples/event-arguments/_config.js
index f2e6c67f8a..4af1ce0070 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-arguments/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-arguments/_config.js
@@ -1,13 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1] = target.querySelectorAll('button');
 
 		b1?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>1</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/event-attribute-after-binding/_config.js b/packages/svelte/tests/runtime-runes/samples/event-attribute-after-binding/_config.js
index e5ec3698e5..b141e87c9d 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-attribute-after-binding/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-attribute-after-binding/_config.js
@@ -1,18 +1,21 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [i1, i2] = target.querySelectorAll('input');
 
 		i1?.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			'true true <input type="checkbox"> false false <input type="checkbox">'
 		);
 
 		i2?.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			'true true <input type="checkbox"> true true <input type="checkbox">'
diff --git a/packages/svelte/tests/runtime-runes/samples/event-attribute-after-spread/_config.js b/packages/svelte/tests/runtime-runes/samples/event-attribute-after-spread/_config.js
index 09975947e6..f520d92e8a 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-attribute-after-spread/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-attribute-after-spread/_config.js
@@ -1,12 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const input = target.querySelector('input');
 
 		input?.dispatchEvent(new Event('input', { bubbles: true }));
-
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, 'true <input class="hello">');
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/event-attribute-capture/_config.js b/packages/svelte/tests/runtime-runes/samples/event-attribute-capture/_config.js
index a0ab696532..4ce0c516ed 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-attribute-capture/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-attribute-capture/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,11 +9,11 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const button = target.querySelector('button');
 
 		button?.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/event-attribute-spread-capture/_config.js b/packages/svelte/tests/runtime-runes/samples/event-attribute-spread-capture/_config.js
index a0ab696532..4ce0c516ed 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-attribute-spread-capture/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-attribute-spread-capture/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,11 +9,11 @@ export default test({
 		</div>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const button = target.querySelector('button');
 
 		button?.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/event-attribute-window/_config.js b/packages/svelte/tests/runtime-runes/samples/event-attribute-window/_config.js
index 1efebf69b7..970064516c 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-attribute-window/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-attribute-window/_config.js
@@ -1,11 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<p>0</p>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		target.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<p>1</p>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/event-exported/_config.js b/packages/svelte/tests/runtime-runes/samples/event-exported/_config.js
index 6dd1f8181e..e8eedc2e96 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-exported/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-exported/_config.js
@@ -1,17 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1, b2] = target.querySelectorAll('button');
 
 		b1?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>Count: 1</button><button>Increment</button>');
 
 		b2?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>Count: 2</button><button>Increment</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/event-listener-spread/_config.js b/packages/svelte/tests/runtime-runes/samples/event-listener-spread/_config.js
index 43084e6809..26e442228b 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-listener-spread/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-listener-spread/_config.js
@@ -1,13 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>clicks: 0</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const button = target.querySelector('button');
 
 		button?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>clicks: 1</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/event-used-in-component-and-element/_config.js b/packages/svelte/tests/runtime-runes/samples/event-used-in-component-and-element/_config.js
index 6dd1f8181e..e8eedc2e96 100644
--- a/packages/svelte/tests/runtime-runes/samples/event-used-in-component-and-element/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/event-used-in-component-and-element/_config.js
@@ -1,17 +1,18 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	mode: ['client'],
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1, b2] = target.querySelectorAll('button');
 
 		b1?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>Count: 1</button><button>Increment</button>');
 
 		b2?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>Count: 2</button><button>Increment</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/exports-1/_config.js b/packages/svelte/tests/runtime-runes/samples/exports-1/_config.js
index 0e447e7055..96323bd0c6 100644
--- a/packages/svelte/tests/runtime-runes/samples/exports-1/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/exports-1/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 0</p><button>Increment</button><button>Decrement</button><button>Double</button>'
@@ -9,21 +10,21 @@ export default test({
 		const [incrementButton, decrementButton, doubleButton] = target.querySelectorAll('button');
 
 		incrementButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 1</p><button>Increment</button><button>Decrement</button><button>Double</button>'
 		);
 
 		doubleButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 2</p><button>Increment</button><button>Decrement</button><button>Double</button>'
 		);
 
 		decrementButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 1</p><button>Increment</button><button>Decrement</button><button>Double</button>'
diff --git a/packages/svelte/tests/runtime-runes/samples/exports-2/_config.js b/packages/svelte/tests/runtime-runes/samples/exports-2/_config.js
index 0e447e7055..96323bd0c6 100644
--- a/packages/svelte/tests/runtime-runes/samples/exports-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/exports-2/_config.js
@@ -1,7 +1,8 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 0</p><button>Increment</button><button>Decrement</button><button>Double</button>'
@@ -9,21 +10,21 @@ export default test({
 		const [incrementButton, decrementButton, doubleButton] = target.querySelectorAll('button');
 
 		incrementButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 1</p><button>Increment</button><button>Decrement</button><button>Double</button>'
 		);
 
 		doubleButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 2</p><button>Increment</button><button>Decrement</button><button>Double</button>'
 		);
 
 		decrementButton?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			'<p>clicks: 1</p><button>Increment</button><button>Decrement</button><button>Double</button>'
diff --git a/packages/svelte/tests/runtime-runes/samples/exports-3/_config.js b/packages/svelte/tests/runtime-runes/samples/exports-3/_config.js
index 6eb043db3d..cf22671d9f 100644
--- a/packages/svelte/tests/runtime-runes/samples/exports-3/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/exports-3/_config.js
@@ -1,12 +1,13 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		assert.htmlEqual(target.innerHTML, `0 0 <button>0 / 0</button>`);
 		const [btn] = target.querySelectorAll('button');
 
 		btn?.click();
-		await Promise.resolve();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '1 2 <button>1 / 2</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/inspect-derived/_config.js b/packages/svelte/tests/runtime-runes/samples/inspect-derived/_config.js
index a8c47665b5..f115c15dfe 100644
--- a/packages/svelte/tests/runtime-runes/samples/inspect-derived/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/inspect-derived/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 /**
@@ -17,14 +18,14 @@ export default test({
 		};
 	},
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const button = target.querySelector('button');
 
 		button?.click();
-		await Promise.resolve();
+		flushSync();
 
 		button?.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.deepEqual(log, ['init', 'X', 'update', 'XX', 'update', 'XXX']);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/invalidate-effect/_config.js b/packages/svelte/tests/runtime-runes/samples/invalidate-effect/_config.js
index b4ba660ad4..1562c8f88c 100644
--- a/packages/svelte/tests/runtime-runes/samples/invalidate-effect/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/invalidate-effect/_config.js
@@ -1,12 +1,13 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		assert.htmlEqual(target.innerHTML, 'a\n<select></select><button>change</button');
 
 		const [b1] = target.querySelectorAll('button');
 		b1.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/mutation-both/_config.js b/packages/svelte/tests/runtime-runes/samples/mutation-both/_config.js
index 1cfc074cf5..6d13ffe84f 100644
--- a/packages/svelte/tests/runtime-runes/samples/mutation-both/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/mutation-both/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -7,7 +8,7 @@ export default test({
   <button>Increase count</button>
   `,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [multiplier, count] = target.querySelectorAll('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
 		const span = /** @type {HTMLSpanElement} */ (target.querySelector('span'));
@@ -19,16 +20,20 @@ export default test({
 		const expect_span_to_be = (count, multiplier) =>
 			assert.htmlEqual(span.innerHTML, `${count} * ${multiplier} = ${count * multiplier}`);
 
-		await count.dispatchEvent(clickEvent);
+		count.dispatchEvent(clickEvent);
+		flushSync();
 		expect_span_to_be(1, 2);
 
-		await multiplier.dispatchEvent(clickEvent);
+		multiplier.dispatchEvent(clickEvent);
+		flushSync();
 		expect_span_to_be(1, 3);
 
-		await count.dispatchEvent(clickEvent);
+		count.dispatchEvent(clickEvent);
+		flushSync();
 		expect_span_to_be(2, 3);
 
-		await multiplier.dispatchEvent(clickEvent);
+		multiplier.dispatchEvent(clickEvent);
+		flushSync();
 		expect_span_to_be(2, 4);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/mutation/_config.js b/packages/svelte/tests/runtime-runes/samples/mutation/_config.js
index af8ead3929..9c666942f0 100644
--- a/packages/svelte/tests/runtime-runes/samples/mutation/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/mutation/_config.js
@@ -1,16 +1,19 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>1 / false</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
 
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1 / true</button>`);
 
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>1 / false</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/nested-destructure-assignment/_config.js b/packages/svelte/tests/runtime-runes/samples/nested-destructure-assignment/_config.js
index 905e8b5d29..497939900e 100644
--- a/packages/svelte/tests/runtime-runes/samples/nested-destructure-assignment/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/nested-destructure-assignment/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -14,10 +15,11 @@ export default test({
 		<p>16</p>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const button = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await button?.dispatchEvent(clickEvent);
+		button?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/not-actual-runes/_config.js b/packages/svelte/tests/runtime-runes/samples/not-actual-runes/_config.js
index 8d4d781076..83cd12f640 100644
--- a/packages/svelte/tests/runtime-runes/samples/not-actual-runes/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/not-actual-runes/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,9 +7,10 @@ export default test({
   <button>Shouldnt be reactive</button>
   `,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/pre-effect/_config.js b/packages/svelte/tests/runtime-runes/samples/pre-effect/_config.js
index 384356dc07..c836a2e593 100644
--- a/packages/svelte/tests/runtime-runes/samples/pre-effect/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/pre-effect/_config.js
@@ -1,11 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const [b1, b2] = target.querySelectorAll('button');
 		b1.click();
 		b2.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.deepEqual(logs, [0, 1]);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/props-alias/_config.js b/packages/svelte/tests/runtime-runes/samples/props-alias/_config.js
index 0fc80f0df5..a0ab706edc 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-alias/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-alias/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,14 +10,14 @@ export default test({
 	<button>0</button>
 	`,
 
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		const [b1, b2, b3, b4] = target.querySelectorAll('button');
 
 		b1.click();
 		b2.click();
 		b3.click();
 		b4.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/props-bound-fallback/_config.js b/packages/svelte/tests/runtime-runes/samples/props-bound-fallback/_config.js
index 3839cb0250..d04d8884ca 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-bound-fallback/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-bound-fallback/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // Tests that fallback value is propagated up correctly when the inner component
@@ -6,10 +7,11 @@ export default test({
 	accessors: false, // so that prop actually becomes $.prop and not $.prop_source
 	html: `<button>0</button><span>0</span>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>1</button><span>1</span>`);
 	},
diff --git a/packages/svelte/tests/runtime-runes/samples/props-bound-to-normal/_config.js b/packages/svelte/tests/runtime-runes/samples/props-bound-to-normal/_config.js
index aaf8f3b193..39eadeac90 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-bound-to-normal/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-bound-to-normal/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,16 +7,19 @@ export default test({
 	async test({ assert, target }) {
 		const [btn1, btn2, btn3] = target.querySelectorAll('button');
 
-		await btn1.click();
-		await Promise.resolve();
+		btn1.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>1</button><button>1</button><button>1</button>`);
 
-		await btn3.click();
-		await Promise.resolve();
+		btn3.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>1</button><button>1</button><button>0</button>`);
 
-		await btn2.click();
-		await Promise.resolve();
+		btn2.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>0</button><button>0</button><button>0</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/props-bound/_config.js b/packages/svelte/tests/runtime-runes/samples/props-bound/_config.js
index 0fc80f0df5..a0ab706edc 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-bound/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-bound/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -9,14 +10,14 @@ export default test({
 	<button>0</button>
 	`,
 
-	async test({ assert, target, component }) {
+	test({ assert, target, component }) {
 		const [b1, b2, b3, b4] = target.querySelectorAll('button');
 
 		b1.click();
 		b2.click();
 		b3.click();
 		b4.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(
 			target.innerHTML,
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-behavior/_config.js b/packages/svelte/tests/runtime-runes/samples/props-default-value-behavior/_config.js
index 47f48b5c20..0b337d7bcb 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-default-value-behavior/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-behavior/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // Tests that default values apply every time and that they propagate back correctly for bindings
@@ -59,7 +60,7 @@ export default test({
 	<button>set everything to undefined</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [
 			btn_5_1,
 			btn_undefined_1,
@@ -77,7 +78,8 @@ export default test({
 		btn_undefined_2.click();
 		btn_undefined_3.click();
 		btn_undefined_4.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -140,7 +142,8 @@ export default test({
 		btn_5_2.click();
 		btn_5_3.click();
 		btn_5_4.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -199,8 +202,9 @@ export default test({
 		`
 		);
 
-		await btn_all_10.click();
-		await Promise.resolve();
+		btn_all_10.click();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -259,8 +263,9 @@ export default test({
 		`
 		);
 
-		await btn_all_undefined.click();
-		await Promise.resolve();
+		btn_all_undefined.click();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/props-spread-fallback/_config.js b/packages/svelte/tests/runtime-runes/samples/props-spread-fallback/_config.js
index 40ad73aa87..2fc8dd0fb9 100644
--- a/packages/svelte/tests/runtime-runes/samples/props-spread-fallback/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/props-spread-fallback/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 // Tests that fallback values are kept as long as the prop is not defined in the case of a spread
@@ -9,10 +10,11 @@ export default test({
 		<p>true fallback</p>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [propA, propB] = target.querySelectorAll('button');
 
-		await propA.click();
+		propA.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -22,7 +24,8 @@ export default test({
 			`
 		);
 
-		await propB.click();
+		propB.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -32,7 +35,8 @@ export default test({
 			`
 		);
 
-		await propA.click();
+		propA.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -42,7 +46,8 @@ export default test({
 			`
 		);
 
-		await propB.click();
+		propB.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/readonly-state-replace/_config.js b/packages/svelte/tests/runtime-runes/samples/readonly-state-replace/_config.js
index 41d9e4061a..38163eb526 100644
--- a/packages/svelte/tests/runtime-runes/samples/readonly-state-replace/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/readonly-state-replace/_config.js
@@ -1,10 +1,11 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const [b1] = target.querySelectorAll('button');
 		b1.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>0, 1</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/readonly-state/_config.js b/packages/svelte/tests/runtime-runes/samples/readonly-state/_config.js
index 384356dc07..c836a2e593 100644
--- a/packages/svelte/tests/runtime-runes/samples/readonly-state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/readonly-state/_config.js
@@ -1,11 +1,12 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const [b1, b2] = target.querySelectorAll('button');
 		b1.click();
 		b2.click();
-		await Promise.resolve();
+		flushSync();
 
 		assert.deepEqual(logs, [0, 1]);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/runes-in-module-context/_config.js b/packages/svelte/tests/runtime-runes/samples/runes-in-module-context/_config.js
index 09bd0a9aad..2ce8bf7e3f 100644
--- a/packages/svelte/tests/runtime-runes/samples/runes-in-module-context/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/runes-in-module-context/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const btn = target.querySelector('button');
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await btn?.dispatchEvent(clickEvent);
+		btn?.dispatchEvent(clickEvent);
+		flushSync();
 
 		assert.htmlEqual(target.innerHTML, `<button>2</button>`);
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured-multiple/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured-multiple/_config.js
index e756ff5cc2..ccd32ffe8c 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured-multiple/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured-multiple/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured/_config.js
index b7b3133c30..5638cb79ca 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-argument-destructured/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-argument-multiple/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-argument-multiple/_config.js
index e756ff5cc2..ccd32ffe8c 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-argument-multiple/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-argument-multiple/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-argument/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-argument/_config.js
index b7b3133c30..5638cb79ca 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-argument/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-argument/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-complicated-defaults/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-complicated-defaults/_config.js
index 4a403b3281..9b21023bf0 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-complicated-defaults/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-complicated-defaults/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -14,17 +15,22 @@ export default test({
 		assert.htmlEqual(count?.innerHTML ?? '', 'Count: 0');
 		assert.htmlEqual(fallback_count?.innerHTML ?? '', 'Fallback count: 0');
 
-		await increment?.click();
+		increment?.click();
+		flushSync();
 		assert.htmlEqual(count?.innerHTML ?? '', 'Count: 1');
 		assert.htmlEqual(fallback_count?.innerHTML ?? '', 'Fallback count: 0');
 
-		await change_ref?.click();
-		await increment?.click();
+		change_ref?.click();
+		flushSync();
+		increment?.click();
+		flushSync();
 		assert.htmlEqual(count?.innerHTML ?? '', 'Count: 1');
 		assert.htmlEqual(fallback_count?.innerHTML ?? '', 'Fallback count: 1');
 
-		await change_ref?.click();
-		await increment?.click();
+		change_ref?.click();
+		flushSync();
+		increment?.click();
+		flushSync();
 		assert.htmlEqual(count?.innerHTML ?? '', 'Count: 2');
 		assert.htmlEqual(fallback_count?.innerHTML ?? '', 'Fallback count: 1');
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-const/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-const/_config.js
index 8867993dbb..d0c32d4097 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-const/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-const/_config.js
@@ -1,16 +1,19 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>0</button>`,
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
 		assert.htmlEqual(target.innerHTML, '<button>0</button>');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>2</button>');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, '<button>4</button>');
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-expressions/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-expressions/_config.js
index 99568fe493..e411862c8f 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-expressions/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-expressions/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -20,9 +21,10 @@ export default test({
 		<button>toggle</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-optional-arguments/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-optional-arguments/_config.js
index 203cb1c432..6007d56cfe 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-optional-arguments/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-optional-arguments/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -8,7 +9,8 @@ export default test({
 		assert.htmlEqual(count?.innerHTML ?? '', '0');
 		assert.htmlEqual(fallback?.innerHTML ?? '', 'fallback');
 
-		await count?.click();
+		count?.click();
+		flushSync();
 		assert.htmlEqual(count?.innerHTML ?? '', '1');
 		assert.htmlEqual(fallback?.innerHTML ?? '', 'fallback');
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-prop-explicit/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-prop-explicit/_config.js
index b7b3133c30..5638cb79ca 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-prop-explicit/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-prop-explicit/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-prop-implicit/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-prop-implicit/_config.js
index b7b3133c30..5638cb79ca 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-prop-implicit/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-prop-implicit/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
 		<button>click me</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-prop-reactive/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-prop-reactive/_config.js
index 89d4713cc0..fb5ee6b14b 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-prop-reactive/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-prop-reactive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,9 +7,10 @@ export default test({
 		<button>show bar</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/snippet-reactive/_config.js b/packages/svelte/tests/runtime-runes/samples/snippet-reactive/_config.js
index 89d4713cc0..fb5ee6b14b 100644
--- a/packages/svelte/tests/runtime-runes/samples/snippet-reactive/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/snippet-reactive/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,9 +7,10 @@ export default test({
 		<button>show bar</button>
 	`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/state-snapshot/_config.js b/packages/svelte/tests/runtime-runes/samples/state-snapshot/_config.js
index 1088a5189c..bcbb4819df 100644
--- a/packages/svelte/tests/runtime-runes/samples/state-snapshot/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/state-snapshot/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `[{"a":0}] <button>[{"a":0}]</button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `[{"a":0}] <button>[{"a":0},{"a":1}]</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/state-space/_config.js b/packages/svelte/tests/runtime-runes/samples/state-space/_config.js
index 2f7c0d88ac..2850ae43ef 100644
--- a/packages/svelte/tests/runtime-runes/samples/state-space/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/state-space/_config.js
@@ -1,12 +1,14 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button type="button">Update Text</button><div></div>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`<button type="button">Update Text</button><div>updated</div>`
diff --git a/packages/svelte/tests/runtime-runes/samples/state-undefined/_config.js b/packages/svelte/tests/runtime-runes/samples/state-undefined/_config.js
index e012718f83..624096fae9 100644
--- a/packages/svelte/tests/runtime-runes/samples/state-undefined/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/state-undefined/_config.js
@@ -1,12 +1,15 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button></button>`,
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
+
 		assert.htmlEqual(target.innerHTML, `<button>foo</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/store-subscribe-effect-init/_config.js b/packages/svelte/tests/runtime-runes/samples/store-subscribe-effect-init/_config.js
index 5672e0806d..4983b8dba9 100644
--- a/packages/svelte/tests/runtime-runes/samples/store-subscribe-effect-init/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/store-subscribe-effect-init/_config.js
@@ -1,17 +1,20 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: `<button>increment</button>`,
 
-	async test({ assert, target, logs }) {
+	test({ assert, target, logs }) {
 		const btn = target.querySelector('button');
 
 		assert.deepEqual(logs, [1]);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.deepEqual(logs, [1, 2]);
 
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.deepEqual(logs, [1, 2, 3]);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/typescript/_config.js b/packages/svelte/tests/runtime-runes/samples/typescript/_config.js
index 2115ae298a..7c9552b7b2 100644
--- a/packages/svelte/tests/runtime-runes/samples/typescript/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/typescript/_config.js
@@ -1,11 +1,13 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
 	html: '<button>clicks: 0</button>',
 
-	async test({ assert, target }) {
+	test({ assert, target }) {
 		const btn = target.querySelector('button');
-		await btn?.click();
+		btn?.click();
+		flushSync();
 		assert.htmlEqual(target.innerHTML, `<button>clicks: 1</button>`);
 	}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/untracked/_config.js b/packages/svelte/tests/runtime-runes/samples/untracked/_config.js
index c3a3f87c5c..f4cde486ec 100644
--- a/packages/svelte/tests/runtime-runes/samples/untracked/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/untracked/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,12 +7,13 @@ export default test({
 	<button>result: 0</button>
 	`,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const [b1, b2] = target.querySelectorAll('button');
 
 		b1.click();
 		b2.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -21,7 +23,8 @@ export default test({
 		);
 
 		b1.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -31,7 +34,8 @@ export default test({
 		);
 
 		b2.click();
-		await Promise.resolve();
+		flushSync();
+
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/wrapped-$state-2/_config.js b/packages/svelte/tests/runtime-runes/samples/wrapped-$state-2/_config.js
index 0f64191847..95668cc0b5 100644
--- a/packages/svelte/tests/runtime-runes/samples/wrapped-$state-2/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/wrapped-$state-2/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -5,9 +6,10 @@ export default test({
   <button>foo</button>
 `,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const clickEvent = new window.Event('click', { bubbles: true });
-		await target.querySelector('button')?.dispatchEvent(clickEvent);
+		target.querySelector('button')?.dispatchEvent(clickEvent);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
diff --git a/packages/svelte/tests/runtime-runes/samples/wrapped-$state/_config.js b/packages/svelte/tests/runtime-runes/samples/wrapped-$state/_config.js
index 5c2bf9e6b4..7238fedca7 100644
--- a/packages/svelte/tests/runtime-runes/samples/wrapped-$state/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/wrapped-$state/_config.js
@@ -1,3 +1,4 @@
+import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
@@ -6,10 +7,11 @@ export default test({
   <p>x</p>
 `,
 
-	async test({ assert, target, window }) {
+	test({ assert, target, window }) {
 		const clickEvent = new window.Event('click', { bubbles: true });
 
-		await target.querySelector('button')?.dispatchEvent(clickEvent);
+		target.querySelector('button')?.dispatchEvent(clickEvent);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`
@@ -20,7 +22,8 @@ export default test({
     `
 		);
 
-		await target.querySelectorAll('button')[1].dispatchEvent(clickEvent);
+		target.querySelectorAll('button')[1].dispatchEvent(clickEvent);
+		flushSync();
 		assert.htmlEqual(
 			target.innerHTML,
 			`