fix(lib)!: remove format prefixes for cjs and esm (#8107)

packages/vite/src/node/__tests__/build.spec.ts

@@ -33,7 +33,7 @@ describe('resolveLibFilename', () => {
       resolve(__dirname, 'packages/name')
     )
 
-    expect(filename).toBe('custom-filename.es.mjs')
+    expect(filename).toBe('custom-filename.mjs')
   })
 
   test('package name as filename', () => {
@@ -45,7 +45,7 @@ describe('resolveLibFilename', () => {
       resolve(__dirname, 'packages/name')
     )
 
-    expect(filename).toBe('mylib.es.mjs')
+    expect(filename).toBe('mylib.mjs')
   })
 
   test('custom filename and no package name', () => {
@@ -58,7 +58,7 @@ describe('resolveLibFilename', () => {
       resolve(__dirname, 'packages/noname')
     )
 
-    expect(filename).toBe('custom-filename.es.mjs')
+    expect(filename).toBe('custom-filename.mjs')
   })
 
   test('missing filename', () => {
@@ -75,9 +75,9 @@ describe('resolveLibFilename', () => {
 
   test('commonjs package extensions', () => {
     const formatsToFilenames: FormatsToFileNames = [
-      ['es', 'my-lib.es.mjs'],
+      ['es', 'my-lib.mjs'],
       ['umd', 'my-lib.umd.js'],
-      ['cjs', 'my-lib.cjs.js'],
+      ['cjs', 'my-lib.js'],
       ['iife', 'my-lib.iife.js']
     ]
 
@@ -94,9 +94,9 @@ describe('resolveLibFilename', () => {
 
   test('module package extensions', () => {
     const formatsToFilenames: FormatsToFileNames = [
-      ['es', 'my-lib.es.js'],
+      ['es', 'my-lib.js'],
       ['umd', 'my-lib.umd.cjs'],
-      ['cjs', 'my-lib.cjs.cjs'],
+      ['cjs', 'my-lib.cjs'],
       ['iife', 'my-lib.iife.js']
     ]
 
@@ -107,7 +107,7 @@ describe('resolveLibFilename', () => {
         resolve(__dirname, 'packages/module')
       )
 
-      expect(filename).toBe(expectedFilename)
+      expect(expectedFilename).toBe(filename)
     }
   })
 })

packages/vite/src/node/build.ts

@@ -596,6 +596,10 @@ export function resolveLibFilename(
     extension = format === 'es' ? 'mjs' : 'js'
   }
 
+  if (format === 'cjs' || format === 'es') {
+    return `${name}.${extension}`
+  }
+
   return `${name}.${format}.${extension}`
 }
 

playground/lib/index.dist.html

@@ -5,7 +5,7 @@
 <div class="dynamic-import-message"></div>
 
 <script type="module">
-  import myLib from './my-lib-custom-filename.es.mjs'
+  import myLib from './my-lib-custom-filename.mjs'
 
   myLib('.es')
 </script>

playground/resolve-config/__tests__/resolve-config.spec.ts

@@ -11,7 +11,7 @@ const build = (configName: string) => {
 
 const getDistFile = (configName: string, extension: string) => {
   return fs.readFileSync(
-    fromTestDir(`${configName}/dist/index.es.${extension}`),
+    fromTestDir(`${configName}/dist/index.${extension}`),
     'utf8'
   )
 }

playground/vue-lib/src-consumer/index.ts

@@ -1,8 +1,7 @@
-/* eslint-disable node/no-missing-import */
+import { createApp } from 'vue'
 // @ts-ignore
-import { CompA } from '../dist/lib/my-vue-lib.es'
+import { CompA } from '../dist/lib/my-vue-lib'
 import '../dist/lib/style.css'
-import { createApp } from 'vue'
 
 const app = createApp(CompA)
 app.mount('#app')