From 5b3d26cae62588981f75165c7dee9c5550aa0e86 Mon Sep 17 00:00:00 2001
From: Alex Snezhko <alexsnezhko89@gmail.com>
Date: Fri, 20 Jun 2025 19:46:25 -0700
Subject: [PATCH] fix(compiler-sfc): check lang before attempt to compile
 script

---
 .../__tests__/compileScript.spec.ts           | 15 +++++++++++++
 packages/compiler-sfc/src/compileScript.ts    | 22 ++++++++++++++++---
 packages/compiler-sfc/src/script/context.ts   | 13 +++--------
 .../compiler-sfc/src/script/normalScript.ts   |  4 ----
 packages/compiler-sfc/src/script/utils.ts     |  5 +++++
 5 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/packages/compiler-sfc/__tests__/compileScript.spec.ts b/packages/compiler-sfc/__tests__/compileScript.spec.ts
index 73c6d316a40..dc3eec6bbd9 100644
--- a/packages/compiler-sfc/__tests__/compileScript.spec.ts
+++ b/packages/compiler-sfc/__tests__/compileScript.spec.ts
@@ -1543,4 +1543,19 @@ describe('compileScript', () => {
     )
     assertCode(content)
   })
+
+  test('should not compile unrecognized language', () => {
+    const { content, lang, scriptAst } = compile(
+      `<script lang="coffee">
+      export default
+        data: ->
+          myVal: 0
+      </script>`,
+    )
+    expect(content).toMatch(`export default
+        data: ->
+          myVal: 0`)
+    expect(lang).toBe('coffee')
+    expect(scriptAst).not.toBeDefined()
+  })
 })
diff --git a/packages/compiler-sfc/src/compileScript.ts b/packages/compiler-sfc/src/compileScript.ts
index 2e1e0ec34de..b3b1d526464 100644
--- a/packages/compiler-sfc/src/compileScript.ts
+++ b/packages/compiler-sfc/src/compileScript.ts
@@ -55,7 +55,13 @@ import { DEFINE_EXPOSE, processDefineExpose } from './script/defineExpose'
 import { DEFINE_OPTIONS, processDefineOptions } from './script/defineOptions'
 import { DEFINE_SLOTS, processDefineSlots } from './script/defineSlots'
 import { DEFINE_MODEL, processDefineModel } from './script/defineModel'
-import { getImportedName, isCallOf, isLiteralNode } from './script/utils'
+import {
+  getImportedName,
+  isCallOf,
+  isJS,
+  isLiteralNode,
+  isTS,
+} from './script/utils'
 import { analyzeScriptBindings } from './script/analyzeScriptBindings'
 import { isImportUsed } from './script/importUsageCheck'
 import { processAwait } from './script/topLevelAwait'
@@ -167,18 +173,26 @@ export function compileScript(
     )
   }
 
-  const ctx = new ScriptCompileContext(sfc, options)
   const { script, scriptSetup, source, filename } = sfc
   const hoistStatic = options.hoistStatic !== false && !script
   const scopeId = options.id ? options.id.replace(/^data-v-/, '') : ''
   const scriptLang = script && script.lang
   const scriptSetupLang = scriptSetup && scriptSetup.lang
+  const isJSOrTS =
+    isJS(scriptLang, scriptSetupLang) || isTS(scriptLang, scriptSetupLang)
 
   if (!scriptSetup) {
     if (!script) {
       throw new Error(`[@vue/compiler-sfc] SFC contains no <script> tags.`)
     }
+
     // normal <script> only
+    if (script.lang && !isJSOrTS) {
+      // do not process non js/ts script blocks
+      return script
+    }
+
+    const ctx = new ScriptCompileContext(sfc, options)
     return processNormalScript(ctx, scopeId)
   }
 
@@ -189,11 +203,13 @@ export function compileScript(
     )
   }
 
-  if (scriptSetupLang && !ctx.isJS && !ctx.isTS) {
+  if (scriptSetupLang && !isJSOrTS) {
     // do not process non js/ts script blocks
     return scriptSetup
   }
 
+  const ctx = new ScriptCompileContext(sfc, options)
+
   // metadata that needs to be returned
   // const ctx.bindingMetadata: BindingMetadata = {}
   const scriptBindings: Record<string, BindingTypes> = Object.create(null)
diff --git a/packages/compiler-sfc/src/script/context.ts b/packages/compiler-sfc/src/script/context.ts
index 47b6b442a49..3d6a129161f 100644
--- a/packages/compiler-sfc/src/script/context.ts
+++ b/packages/compiler-sfc/src/script/context.ts
@@ -9,6 +9,7 @@ import type { BindingMetadata } from '../../../compiler-core/src'
 import MagicString from 'magic-string'
 import type { TypeScope } from './resolveType'
 import { warn } from '../warn'
+import { isJS, isTS } from './utils'
 
 export class ScriptCompileContext {
   isJS: boolean
@@ -87,16 +88,8 @@ export class ScriptCompileContext {
     const scriptLang = script && script.lang
     const scriptSetupLang = scriptSetup && scriptSetup.lang
 
-    this.isJS =
-      scriptLang === 'js' ||
-      scriptLang === 'jsx' ||
-      scriptSetupLang === 'js' ||
-      scriptSetupLang === 'jsx'
-    this.isTS =
-      scriptLang === 'ts' ||
-      scriptLang === 'tsx' ||
-      scriptSetupLang === 'ts' ||
-      scriptSetupLang === 'tsx'
+    this.isJS = isJS(scriptLang, scriptSetupLang)
+    this.isTS = isTS(scriptLang, scriptSetupLang)
 
     const customElement = options.customElement
     const filename = this.descriptor.filename
diff --git a/packages/compiler-sfc/src/script/normalScript.ts b/packages/compiler-sfc/src/script/normalScript.ts
index 7fd859290b1..b019fe110d8 100644
--- a/packages/compiler-sfc/src/script/normalScript.ts
+++ b/packages/compiler-sfc/src/script/normalScript.ts
@@ -12,10 +12,6 @@ export function processNormalScript(
   scopeId: string,
 ): SFCScriptBlock {
   const script = ctx.descriptor.script!
-  if (script.lang && !ctx.isJS && !ctx.isTS) {
-    // do not process non js/ts script blocks
-    return script
-  }
   try {
     let content = script.content
     let map = script.map
diff --git a/packages/compiler-sfc/src/script/utils.ts b/packages/compiler-sfc/src/script/utils.ts
index 39f163c6b77..1b7da0e3497 100644
--- a/packages/compiler-sfc/src/script/utils.ts
+++ b/packages/compiler-sfc/src/script/utils.ts
@@ -121,3 +121,8 @@ export const propNameEscapeSymbolsRE: RegExp =
 export function getEscapedPropName(key: string): string {
   return propNameEscapeSymbolsRE.test(key) ? JSON.stringify(key) : key
 }
+
+export const isJS = (...langs: (string | null | undefined)[]): boolean =>
+  langs.some(lang => lang === 'js' || lang === 'jsx')
+export const isTS = (...langs: (string | null | undefined)[]): boolean =>
+  langs.some(lang => lang === 'ts' || lang === 'tsx')