fix(vite-node): fix esm false-detection inside comment (#6506)

packages/vite-node/src/externalize.ts

@@ -11,6 +11,9 @@ const ESM_SYNTAX_RE
 const ESM_EXT_RE = /\.(es|esm|esm-browser|esm-bundler|es6|module)\.js$/
 const ESM_FOLDER_RE = /\/(es|esm)\/(.*\.js)$/
 
+// https://stackoverflow.com/a/15123777
+const COMMENT_RE = /\/\*[\s\S]*?\*\/|([^\\:]|^)\/\/.*$/gm
+
 const defaultInline = [
   /virtual:/,
   /\.[mc]?ts$/,
@@ -79,7 +82,7 @@ async function isValidNodeImport(id: string) {
 
   const code = await fsp.readFile(id, 'utf8').catch(() => '')
 
-  return !ESM_SYNTAX_RE.test(code)
+  return !ESM_SYNTAX_RE.test(code.replace(COMMENT_RE, ''))
 }
 
 const _defaultExternalizeCache = new Map<string, Promise<string | false>>()

test/core/deps/dep-esm-comment/index.js

@@ -0,0 +1,6 @@
+// import x from "x"
+/** import x from "x" */
+/**
+ * import x from "x"
+ */
+module.exports = { test: 'ok' }

test/core/deps/dep-esm-comment/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "@vitest/test-dep-esm-comment",
+  "type": "commonjs",
+  "exports": "./index.js"
+}

test/core/package.json

@@ -16,6 +16,7 @@
     "@vitest/expect": "workspace:*",
     "@vitest/mocker": "workspace:*",
     "@vitest/runner": "workspace:*",
+    "@vitest/test-dep-esm-comment": "file:./deps/dep-esm-comment",
     "@vitest/test-dep1": "file:./deps/dep1",
     "@vitest/test-dep2": "file:./deps/dep2",
     "@vitest/utils": "workspace:*",

test/core/test/dual-package-hazard.test.ts

@@ -1,3 +1,4 @@
+import { createRequire } from 'node:module'
 import { expect, test } from 'vitest'
 
 // @ts-expect-error no ts
@@ -6,7 +7,17 @@ import * as dep1 from '@vitest/test-dep1'
 // @ts-expect-error no ts
 import * as dep2 from '@vitest/test-dep2'
 
+// @ts-expect-error no ts
+import depEsmComment from '@vitest/test-dep-esm-comment'
+
+const require = createRequire(import.meta.url)
+
 test('no dual package hazard by externalizing esm deps by default', async () => {
   dep1.data.hello = 'world'
   expect(dep2.data.hello).toBe('world')
 })
+
+test('externalize cjs with esm comment', async () => {
+  const depEsmCommentRequire = require('@vitest/test-dep-esm-comment')
+  expect(depEsmComment).toBe(depEsmCommentRequire)
+})