From 6f8068637c6f18649d17687c588b06381318d578 Mon Sep 17 00:00:00 2001
From: Simon H <5968653+dummdidumm@users.noreply.github.com>
Date: Mon, 31 Mar 2025 16:48:42 +0200
Subject: [PATCH] fix: support TS type assertions (#15642)

fixes #15565
---
 .changeset/lovely-windows-hang.md                            | 5 +++++
 .../src/compiler/phases/1-parse/remove_typescript_nodes.js   | 3 +++
 .../tests/runtime-runes/samples/typescript/main.svelte       | 1 +
 3 files changed, 9 insertions(+)
 create mode 100644 .changeset/lovely-windows-hang.md

diff --git a/.changeset/lovely-windows-hang.md b/.changeset/lovely-windows-hang.md
new file mode 100644
index 0000000000..406e6c4961
--- /dev/null
+++ b/.changeset/lovely-windows-hang.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: support TS type assertions
diff --git a/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js b/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
index 09eb0bfa68..37dc0e17a1 100644
--- a/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
+++ b/packages/svelte/src/compiler/phases/1-parse/remove_typescript_nodes.js
@@ -94,6 +94,9 @@ const visitors = {
 	TSTypeAliasDeclaration() {
 		return b.empty;
 	},
+	TSTypeAssertion(node, context) {
+		return context.visit(node.expression);
+	},
 	TSEnumDeclaration(node) {
 		e.typescript_invalid_feature(node, 'enums');
 	},
diff --git a/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte b/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
index e2942b21f3..d2a9da5439 100644
--- a/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/typescript/main.svelte
@@ -45,6 +45,7 @@
 	export type { Hello };
 
 	const TypedFoo = Foo<true>;
+	const typeAssertion = <boolean>true;
 </script>
 
 <script>