chore: add workaround for .mjs extension

packages/browser/src/client/main.ts

@@ -57,6 +57,8 @@ ws.addEventListener('open', async () => {
   const { getSafeTimers } = await importId('vitest/utils') as typeof import('vitest/utils')
   const safeRpc = createSafeRpc(client, getSafeTimers)
 
+  // @ts-expect-error untyped global for internal use
+  globalThis.__vitest_browser__ = true
   // @ts-expect-error mocking vitest apis
   globalThis.__vitest_worker__ = {
     config,

packages/browser/src/node/index.ts

@@ -18,12 +18,6 @@ export default (base = '/'): Plugin[] => {
     {
       enforce: 'pre',
       name: 'vitest:browser',
-      async resolveId(id, importer, options) {
-        if (id.includes('?vitest='))
-          // Work-around for vite:resolve. The "import('./file.mjs?vitest=123')" fails to load "./file.mts" and throws error.
-          // This is fixed in Vite 4.3.0
-          return this.resolve(id.split('?vitest=')[0], importer, options)
-      },
       async config(viteConfig) {
         // Enables using ignore hint for coverage providers with @preserve keyword
         viteConfig.esbuild ||= {}

test/coverage-test/test/coverage.test.ts

@@ -1,8 +1,16 @@
 import { expect, test } from 'vitest'
-import { pythagoras } from '../src/index.mjs'
 import { implicitElse } from '../src/implicitElse'
 import { useImportEnv } from '../src/importEnv'
 
+const { pythagoras } = await (() => {
+  if ('__vitest_browser__' in globalThis)
+    // TODO: remove workaround after vite 4.3.2
+    // @ts-expect-error extension is not specified
+    return import('../src/index')
+  const dynamicImport = '../src/index.mjs'
+  return import(dynamicImport)
+})()
+
 test('Math.sqrt()', async () => {
   expect(pythagoras(3, 4)).toBe(5)
 })