perf: optimize module resolution of compiled packages (#6274)

Author: chenjiahan

packages/core/prebundle.config.mjs

@@ -53,7 +53,7 @@ export default {
       name: 'launch-editor-middleware',
       ignoreDts: true,
       externals: {
-        picocolors: '../picocolors',
+        picocolors: '../picocolors/index.js',
       },
     },
     {
@@ -134,7 +134,7 @@ export default {
       name: 'postcss',
       copyDts: true,
       externals: {
-        picocolors: '../picocolors',
+        picocolors: '../picocolors/index.js',
       },
       afterBundle(task) {
         // source-map-js type does not exist, use a stub instead
@@ -160,22 +160,22 @@ export type SourceMapGenerator = unknown;
       name: 'css-loader',
       ignoreDts: true,
       externals: {
-        postcss: '../postcss',
+        postcss: '../postcss/index.js',
       },
     },
     {
       name: 'postcss-loader',
       externals: {
         jiti: 'jiti',
-        postcss: '../postcss',
+        postcss: '../postcss/index.js',
       },
       ignoreDts: true,
     },
     {
       name: '@jridgewell/remapping',
       ignoreDts: true,
       externals: {
-        '@jridgewell/trace-mapping': '../trace-mapping',
+        '@jridgewell/trace-mapping': '../trace-mapping/index.js',
       },
     },
   ],

packages/plugin-babel/prebundle.config.mjs

@@ -1,14 +1,4 @@
 // @ts-check
-import { writeFileSync } from 'node:fs';
-import { join } from 'node:path';
-
-// The package size of `schema-utils` is large, and validate has a performance overhead of tens of ms.
-// So we skip the validation and let TypeScript to ensure type safety.
-const writeEmptySchemaUtils = (task) => {
-  const schemaUtilsPath = join(task.distPath, 'schema-utils.js');
-  writeFileSync(schemaUtilsPath, 'module.exports.validate = () => {};');
-};
-
 /** @type {import('prebundle').Config} */
 export default {
   prettier: true,
@@ -18,9 +8,7 @@ export default {
       ignoreDts: true,
       externals: {
         '@babel/core': '@babel/core',
-        'schema-utils': './schema-utils',
       },
-      afterBundle: writeEmptySchemaUtils,
     },
   ],
 };