From 00734afef5f7bddbdaee52aa5359a6ef989f32d3 Mon Sep 17 00:00:00 2001
From: Runyasak Chaengnaimuang <runyasak.c@gmail.com>
Date: Wed, 21 May 2025 08:06:05 +0700
Subject: [PATCH] fix(compiler-sfc): add error handling for defineModel()
 without variable assignment (#13352)

close #13280
---
 .../compiler-sfc/__tests__/compileScript.spec.ts     |  6 +++---
 .../__tests__/compileScript/defineModel.spec.ts      | 12 ++++++++++++
 packages/compiler-sfc/src/script/defineModel.ts      |  7 +++++++
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/packages/compiler-sfc/__tests__/compileScript.spec.ts b/packages/compiler-sfc/__tests__/compileScript.spec.ts
index 73c6d316a4..b2a8036a0e 100644
--- a/packages/compiler-sfc/__tests__/compileScript.spec.ts
+++ b/packages/compiler-sfc/__tests__/compileScript.spec.ts
@@ -1007,7 +1007,7 @@ describe('SFC compile <script setup>', () => {
       expect(() =>
         compile(`<script setup>
         let bar = 1
-        defineModel({
+        const model = defineModel({
           default: () => bar
         })
         </script>`),
@@ -1017,7 +1017,7 @@ describe('SFC compile <script setup>', () => {
       expect(() =>
         compile(`<script setup>
         const bar = 1
-        defineModel({
+        const model = defineModel({
           default: () => bar
         })
         </script>`),
@@ -1027,7 +1027,7 @@ describe('SFC compile <script setup>', () => {
       expect(() =>
         compile(`<script setup>
         let bar = 1
-        defineModel({
+        const model = defineModel({
           get: () => bar,
           set: () => bar
         })
diff --git a/packages/compiler-sfc/__tests__/compileScript/defineModel.spec.ts b/packages/compiler-sfc/__tests__/compileScript/defineModel.spec.ts
index 5d696a95d8..104d3dc7ab 100644
--- a/packages/compiler-sfc/__tests__/compileScript/defineModel.spec.ts
+++ b/packages/compiler-sfc/__tests__/compileScript/defineModel.spec.ts
@@ -269,4 +269,16 @@ describe('defineModel()', () => {
       modelValue: BindingTypes.SETUP_REF,
     })
   })
+
+  test('error when defineModel is not assigned to a variable', () => {
+    expect(() =>
+      compile(`
+        <script setup>
+        defineModel()
+        </script>
+      `),
+    ).toThrow(
+      'defineModel() must be assigned to a variable. For example: const model = defineModel()',
+    )
+  })
 })
diff --git a/packages/compiler-sfc/src/script/defineModel.ts b/packages/compiler-sfc/src/script/defineModel.ts
index 0508280028..746bbabe55 100644
--- a/packages/compiler-sfc/src/script/defineModel.ts
+++ b/packages/compiler-sfc/src/script/defineModel.ts
@@ -22,6 +22,13 @@ export function processDefineModel(
     return false
   }
 
+  if (!declId) {
+    ctx.error(
+      'defineModel() must be assigned to a variable. For example: const model = defineModel()',
+      node,
+    )
+  }
+
   ctx.hasDefineModelCall = true
 
   const type =
-- 
2.47.2