From 2ca9a816799485e0fc932d8bb86ff03df71d5cad Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Sat, 19 Oct 2024 14:11:55 +0100
Subject: [PATCH] fix: ensure user effects are correctly executed on
 initialisation (#13697)

---
 .changeset/brave-rivers-jam.md                    |  5 +++++
 .../src/internal/client/reactivity/effects.js     |  3 +--
 .../samples/effect-order-5/_config.js             |  7 +++++++
 .../samples/effect-order-5/main.svelte            | 15 +++++++++++++++
 4 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/brave-rivers-jam.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/effect-order-5/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/effect-order-5/main.svelte

diff --git a/.changeset/brave-rivers-jam.md b/.changeset/brave-rivers-jam.md
new file mode 100644
index 0000000000..c8dcd42c0d
--- /dev/null
+++ b/.changeset/brave-rivers-jam.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ensure user effects are correctly executed on initialisation
diff --git a/packages/svelte/src/internal/client/reactivity/effects.js b/packages/svelte/src/internal/client/reactivity/effects.js
index 193c6df145..6e24ce5724 100644
--- a/packages/svelte/src/internal/client/reactivity/effects.js
+++ b/packages/svelte/src/internal/client/reactivity/effects.js
@@ -192,8 +192,7 @@ export function user_effect(fn) {
 	// until the component is mounted
 	var defer =
 		active_effect !== null &&
-		(active_effect.f & RENDER_EFFECT) !== 0 &&
-		// TODO do we actually need this? removing them changes nothing
+		(active_effect.f & BRANCH_EFFECT) !== 0 &&
 		component_context !== null &&
 		!component_context.m;
 
diff --git a/packages/svelte/tests/runtime-runes/samples/effect-order-5/_config.js b/packages/svelte/tests/runtime-runes/samples/effect-order-5/_config.js
new file mode 100644
index 0000000000..2067a5b3dd
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/effect-order-5/_config.js
@@ -0,0 +1,7 @@
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, logs }) {
+		assert.deepEqual(logs, ['effect 1', 'effect 2']);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/effect-order-5/main.svelte b/packages/svelte/tests/runtime-runes/samples/effect-order-5/main.svelte
new file mode 100644
index 0000000000..986cb8d72b
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/effect-order-5/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	$effect.pre(() => {
+		$effect(() => {
+			console.log('effect 1')
+		})
+	})
+
+	function template() {
+		$effect(() => {
+			console.log('effect 2')
+		});
+	}
+</script>
+
+{template()}