From 0854113c28c95b1198d91d7871048c826b9b8354 Mon Sep 17 00:00:00 2001
From: Johnson Chu <johnsoncodehk@gmail.com>
Date: Sat, 6 Dec 2025 04:27:23 +0800
Subject: [PATCH] fix(language-core): AST fault tolerance for key binding on
 template

---
 .../lib/virtualCode/normalize.ts              | 39 ++++++++++++++++++-
 .../tsc/passedFixtures/vue3/#4539/main.vue    |  5 +++
 2 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 test-workspace/tsc/passedFixtures/vue3/#4539/main.vue

diff --git a/packages/language-core/lib/virtualCode/normalize.ts b/packages/language-core/lib/virtualCode/normalize.ts
index e378066d98..a111d0dad9 100644
--- a/packages/language-core/lib/virtualCode/normalize.ts
+++ b/packages/language-core/lib/virtualCode/normalize.ts
@@ -19,7 +19,7 @@ export function normalizeTemplateAST(root: CompilerDOM.RootNode) {
 		expressionPlugins: ['typescript'],
 	};
 
-	for (const { children } of forEachElementNode(root)) {
+	for (const { children, codegenNode, props } of forEachElementNode(root)) {
 		for (let i = 0; i < children.length; i++) {
 			const child = children[i]!;
 			if (child.type !== CompilerDOM.NodeTypes.ELEMENT) {
@@ -37,6 +37,43 @@ export function normalizeTemplateAST(root: CompilerDOM.RootNode) {
 				continue;
 			}
 		}
+		// #4539
+		if (
+			codegenNode
+			&& 'props' in codegenNode
+			&& codegenNode.props
+			&& 'properties' in codegenNode.props
+		) {
+			for (const p of codegenNode.props.properties) {
+				if (
+					p.key.type === CompilerDOM.NodeTypes.SIMPLE_EXPRESSION
+					&& p.key.content === 'key'
+					&& !p.key.isHandlerKey
+					&& !p.key.loc.source
+					&& p.value.type === CompilerDOM.NodeTypes.SIMPLE_EXPRESSION
+					&& p.value.constType === CompilerDOM.ConstantTypes.NOT_CONSTANT
+				) {
+					const contentBeforeValue = root.loc.source.slice(0, p.value.loc.start.offset);
+					const argOffset = contentBeforeValue.lastIndexOf('key');
+					props.push({
+						type: CompilerDOM.NodeTypes.DIRECTIVE,
+						name: 'bind',
+						exp: p.value,
+						loc: p.loc,
+						arg: {
+							...p.key,
+							loc: {
+								start: { line: -1, column: -1, offset: argOffset },
+								end: { line: -1, column: -1, offset: argOffset + 'key'.length },
+								source: 'key',
+							},
+						},
+						modifiers: [],
+					});
+					break;
+				}
+			}
+		}
 	}
 }
 
diff --git a/test-workspace/tsc/passedFixtures/vue3/#4539/main.vue b/test-workspace/tsc/passedFixtures/vue3/#4539/main.vue
new file mode 100644
index 0000000000..1351329a9f
--- /dev/null
+++ b/test-workspace/tsc/passedFixtures/vue3/#4539/main.vue
@@ -0,0 +1,5 @@
+<template>
+    <template v-for="x in [1]" :key="x">
+        <div></div>
+    </template>
+</template>