fix: respect extension of origin import path when redirect.js.extension disabled

Author: Timeless0911

packages/core/src/config.ts

@@ -1448,6 +1448,7 @@ const composeBundlelessExternalConfig = (
               return;
             }
             const { issuer } = contextInfo;
+            const originExtension = extname(request);
 
             if (!resolver) {
               resolver = getResolve() as RspackResolver;
@@ -1497,7 +1498,7 @@ const composeBundlelessExternalConfig = (
                 logger.debug(
                   `Failed to resolve module ${color.green(`"${request}"`)} from ${color.green(issuer)}. If it's an npm package, consider adding it to dependencies or peerDependencies in package.json to make it externalized.`,
                 );
-                return request;
+                return undefined;
               }
             }
 
@@ -1543,12 +1544,14 @@ const composeBundlelessExternalConfig = (
                 if (ext) {
                   // 1. js files hit JS_EXTENSIONS_PATTERN, ./foo.ts -> ./foo.mjs
                   if (JS_EXTENSIONS_PATTERN.test(resolvedRequest)) {
-                    if (jsRedirectExtension) {
-                      resolvedRequest = resolvedRequest.replace(
-                        /\.[^.]+$/,
-                        jsExtension,
-                      );
-                    }
+                    resolvedRequest = resolvedRequest.replace(
+                      /\.[^.]+$/,
+                      jsRedirectExtension
+                        ? jsExtension
+                        : JS_EXTENSIONS_PATTERN.test(originExtension)
+                          ? originExtension
+                          : '',
+                    );
                   } else {
                     // 2. asset files, does not match jsExtensionsPattern, eg: ./foo.png -> ./foo.mjs
                     // non-js && non-css files
@@ -1569,7 +1572,7 @@ const composeBundlelessExternalConfig = (
                     // If the import path refers to a directory,
                     // it most likely actually refers to a `index.*` file due to Node's module resolution.
                     // When redirect.js.path is set to false, index should still be added before adding extension.
-                    // When redirect.js.path is true, the resolver directly generate correct resolvedRequest with index appended.
+                    // When redirect.js.path is set to true, the resolver directly generate correct resolvedRequest with index appended.
                     if (
                       !jsRedirectPath &&
                       (await isDirectory(

packages/plugin-dts/README.md

@@ -233,7 +233,7 @@ const defaultRedirect = {
 };
 ```
 
-Controls the redirect of the import paths of output TypeScript declaration files.
+Controls the redirect of the import paths of TypeScript declaration output files.
 
 ```js
 pluginDts({
@@ -269,9 +269,9 @@ import { foo } from '../foo'; // expected output './dist/utils/index.d.ts'
 - **Type:** `boolean`
 - **Default:** `false`
 
-Whether to automatically redirect the file extension to import paths based on the TypeScript declaration output files.
+Whether to automatically redirect the file extension of import paths based on the TypeScript declaration output files.
 
-- When set to `true`, the import paths in declaration files will be redirected to the corresponding JavaScript extension which can be resolved to corresponding declaration file. The extension of the declaration output file is related to the `dtsExtension` configuration.
+- When set to `true`, the file extension of the import path in the declaration file will be automatically completed or replaced with the corresponding JavaScript file extension that can be resolved to the corresponding declaration file. The extension of the declaration output file is related to the `dtsExtension` configuration.
 
 ```ts
 // `dtsExtension` is set to `.d.mts`
@@ -282,7 +282,7 @@ import { foo } from './foo.ts'; // source code of './src/bar.ts' ↓
 import { foo } from './foo.mjs'; // expected output of './dist/bar.d.mts'
 ```
 
-- When set to `false`, the file extension will remain unchanged from the original import path in the rewritten import path of the output file (regardless of whether it is specified or specified as any value).
+- When set to `false`, import paths will retain their original file extensions.
 
 ### tsgo
 

tests/integration/redirect/js.test.ts

@@ -18,6 +18,18 @@ test('redirect.js default', async () => {
     contents.cjs0!,
     /cjs\/index\.cjs/,
   );
+  const { content: notResolvedContent } = queryContent(
+    contents.esm0!,
+    /esm\/not-resolved\.js/,
+  );
+
+  expect(notResolvedContent).toMatchInlineSnapshot(`
+    "export * from "not_resolved";
+    export * from "./foo.node";
+    export * from "./foo.node.js";
+    export * from "./not_resolved_file";
+    "
+  `);
 
   expect(indexContent).toMatchInlineSnapshot(`
     "import lodash from "lodash";
@@ -28,6 +40,11 @@ test('redirect.js default', async () => {
     import { baz } from "./baz.js";
     export * from "./.hidden.js";
     export * from "./.hidden-folder/index.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./foo.js";
+    export * from "./foo.js";
     const src = lodash.toUpper(lodash_merge(foo) + bar + foo + bar + baz + typeof prettier.version);
     export { src as default };
     "
@@ -46,6 +63,19 @@ test('redirect.js.path false', async () => {
     /esm\/index\.js/,
   );
 
+  const { content: notResolvedContent } = queryContent(
+    contents.esm1!,
+    /esm\/not-resolved\.js/,
+  );
+
+  expect(notResolvedContent).toMatchInlineSnapshot(`
+    "export * from "not_resolved";
+    export * from "./foo.node";
+    export * from "./foo.node.js";
+    export * from "./not_resolved_file";
+    "
+  `);
+
   expect(indexContent).toMatchInlineSnapshot(`
     "import lodash from "lodash";
     import lodash_merge from "lodash.merge";
@@ -57,6 +87,11 @@ test('redirect.js.path false', async () => {
     import { foo as external_foo_js_foo } from "./foo.js";
     export * from "./.hidden.js";
     export * from "./.hidden-folder/index.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./foo.js";
+    export * from "./foo.js";
     const src = lodash.toUpper(lodash_merge(external_foo_js_foo) + index_js_bar + foo + bar + baz + typeof prettier.version);
     export { src as default };
     "
@@ -73,6 +108,19 @@ test('redirect.js.path with user override externals', async () => {
     /cjs\/index\.cjs/,
   );
 
+  const { content: notResolvedContent } = queryContent(
+    contents.esm2!,
+    /esm\/not-resolved\.js/,
+  );
+
+  expect(notResolvedContent).toMatchInlineSnapshot(`
+    "export * from "not_resolved";
+    export * from "./foo.node";
+    export * from "./foo.node.js";
+    export * from "./not_resolved_file";
+    "
+  `);
+
   expect(indexContent).toMatchInlineSnapshot(`
     "import lodash from "lodash";
     import lodash_merge from "lodash.merge";
@@ -84,6 +132,11 @@ test('redirect.js.path with user override externals', async () => {
     import { foo as external_foo_js_foo } from "./foo.js";
     export * from "./.hidden.js";
     export * from "./.hidden-folder/index.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./foo.js";
+    export * from "./foo.js";
     const src = lodash.toUpper(lodash_merge(external_foo_js_foo) + index_js_bar + foo + bar + baz + typeof prettier.version);
     export { src as default };
     "
@@ -108,6 +161,19 @@ test('redirect.js.path with user override alias', async () => {
     /cjs\/index\.cjs/,
   );
 
+  const { content: notResolvedContent } = queryContent(
+    contents.esm3!,
+    /esm\/not-resolved\.js/,
+  );
+
+  expect(notResolvedContent).toMatchInlineSnapshot(`
+    "export * from "not_resolved";
+    export * from "./foo.node";
+    export * from "./foo.node.js";
+    export * from "./not_resolved_file";
+    "
+  `);
+
   expect(indexContent).toMatchInlineSnapshot(`
     "import lodash from "lodash";
     import lodash_merge from "lodash.merge";
@@ -119,6 +185,11 @@ test('redirect.js.path with user override alias', async () => {
     import { foo as external_foo_js_foo } from "./foo.js";
     export * from "./.hidden.js";
     export * from "./.hidden-folder/index.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./bar.node.js";
+    export * from "./foo.js";
+    export * from "./foo.js";
     const src = lodash.toUpper(lodash_merge(external_foo_js_foo) + index_js_bar + foo + bar + baz + typeof prettier.version);
     export { src as default };
     "
@@ -138,15 +209,33 @@ test('redirect.js.extension: false', async () => {
     contents.esm4!,
     /esm\/index\.js/,
   );
+  const { content: notResolvedContent } = queryContent(
+    contents.esm4!,
+    /esm\/not-resolved\.js/,
+  );
+
+  expect(notResolvedContent).toMatchInlineSnapshot(`
+    "export * from "not_resolved";
+    export * from "./foo.node";
+    export * from "./foo.node.js";
+    export * from "./not_resolved_file";
+    "
+  `);
+
   expect(indexContent).toMatchInlineSnapshot(`
     "import lodash from "lodash";
     import lodash_merge from "lodash.merge";
     import prettier from "prettier";
-    import { bar } from "./bar/index.ts";
-    import { foo } from "./foo.ts";
-    import { baz } from "./baz.ts";
-    export * from "./.hidden.ts";
-    export * from "./.hidden-folder/index.ts";
+    import { bar } from "./bar/index";
+    import { foo } from "./foo";
+    import { baz } from "./baz";
+    export * from "./.hidden";
+    export * from "./.hidden-folder/index";
+    export * from "./bar.node";
+    export * from "./bar.node.js";
+    export * from "./bar.node.ts";
+    export * from "./foo.js";
+    export * from "./foo.ts";
     const src = lodash.toUpper(lodash_merge(foo) + bar + foo + bar + baz + typeof prettier.version);
     export { src as default };
     "

tests/integration/redirect/js/src/bar.node.ts

@@ -0,0 +1 @@
+export const bar_node = 'bar node';

tests/integration/redirect/js/src/index.ts

@@ -1,6 +1,5 @@
-// can not be resolved
-import lodash from 'lodash';
 // can be resolved, 3rd party packages
+import lodash from 'lodash';
 import merge from 'lodash.merge';
 // can be resolved but not specified -- phantom dependency
 import prettier from 'prettier';
@@ -14,6 +13,11 @@ import { foo } from './foo';
 
 export * from './.hidden';
 export * from './.hidden-folder';
+export * from './bar.node';
+export * from './bar.node.js';
+export * from './bar.node.ts';
+export * from './foo.js';
+export * from './foo.ts';
 
 export default lodash.toUpper(
   merge(foo) + bar + foo2 + bar2 + baz + typeof prettier.version,

tests/integration/redirect/js/src/not-resolved.ts

@@ -0,0 +1,5 @@
+// @ts-nocheck
+export * from 'not_resolved';
+export * from './foo.node';
+export * from './foo.node.js';
+export * from './not_resolved_file';

tests/integration/redirect/js/tsconfig.json

@@ -2,6 +2,8 @@
   "extends": "@rslib/tsconfig/base",
   "compilerOptions": {
     "baseUrl": "./",
+    "noEmit": true,
+    "allowImportingTsExtensions": true,
     "paths": {
       "@/*": ["./src/*"]
     }

website/docs/en/config/lib/redirect.mdx

@@ -85,7 +85,7 @@ Whether to automatically redirect the import paths of JavaScript output files.
 - **Type:** `boolean`
 - **Default:** `true`
 
-When set to `true`, [resolve.alias](/config/rsbuild/resolve#resolvealias) and [resolve.aliasStrategy](/config/rsbuild/resolve#aliasstrategy) will take effect and applied in the rewritten import path of the output file. For TypeScript projects, just configure [compilerOptions.paths](https://typescriptlang.org/tsconfig#paths) in the `tsconfig.json` file.
+When set to `true`, [resolve.alias](/config/rsbuild/resolve#resolvealias) and [resolve.aliasStrategy](/config/rsbuild/resolve#aliasstrategy) will take effect in the output file, and the import path of the output file will be rewritten. For TypeScript projects, just configure [compilerOptions.paths](https://typescriptlang.org/tsconfig#paths) in the `tsconfig.json` file.
 
 When set to `false`, the import path will not be effected by [resolve.alias](/config/rsbuild/resolve#resolvealias), [resolve.aliasStrategy](/config/rsbuild/resolve#aliasstrategy) and `tsconfig.json`.
 
@@ -103,14 +103,14 @@ import { foo } from '../foo.js'; // expected output './dist/utils/index.js'
 
 ### redirect.js.extension
 
-Whether to automatically redirect the file extension to import paths based on the JavaScript output files.
+Whether to automatically redirect the file extension of import paths based on the JavaScript output files.
 
 - **Type:** `boolean`
 - **Default:** `true`
 
-When set to `true`, the file extension will automatically be added to the rewritten import path of the output file, regardless of the original extension or whether it is specified in the import path.
+When set to `true`, the file extension of import paths in JavaScript output files that can be resolved correctly will be automatically completed or replaced.
 
-When set to `false`, the file extension will remain unchanged from the original import path in the rewritten import path of the output file (regardless of whether it is specified or specified as any value).
+When set to `false`, import paths will retain their original file extensions.
 
 :::note
 The extension of the JavaScript output file is related to the [autoExtension](/config/lib/auto-extension#libautoextension) configuration.
@@ -167,7 +167,7 @@ import styles from '../foo.css'; // expected output of './dist/utils/index.js'
 
 ### redirect.style.extension
 
-Whether to automatically redirect the file extension to import paths based on the style output files.
+Whether to automatically redirect the file extension of import paths based on the style output files.
 
 - **Type:** `boolean`
 - **Default:** `true`
@@ -215,7 +215,7 @@ import url from './assets/logo.svg'; // expected output of './dist/foo.js'
 
 ### redirect.asset.extension
 
-Whether to automatically redirect the file extension to import paths based on the asset output files.
+Whether to automatically redirect the file extension of import paths based on the asset output files.
 
 - **Type:** `boolean`
 - **Default:** `true`
@@ -266,22 +266,22 @@ import { foo } from '../foo'; // expected output './dist/utils/index.d.ts'
 
 ### redirect.dts.extension
 
-Whether to automatically redirect the file extension to import paths based on the TypeScript declaration output files.
+Whether to automatically redirect the file extension of import paths based on the TypeScript declaration output files.
 
 - **Type:** `boolean`
 - **Default:** `false`
 
-When set to `true`, the import paths in declaration files will be redirected to the corresponding JavaScript extension which can be resolved to corresponding declaration file.
+When set to `true`, the file extension of the import path in the declaration file will be automatically completed or replaced with the corresponding JavaScript file extension that can be resolved to the corresponding declaration file.
 
-When set to `false`, the file extension will remain unchanged from the original import path in the rewritten import path of the output file (regardless of whether it is specified or specified as any value).
+When set to `false`, import paths will retain their original file extensions.
 
 :::note
 The extension of the TypeScript declaration file is related to the [dts.autoExtension](/config/lib/dts#dtsautoextension) configuration.
 :::
 
 - **Example:**
 
-For the `.d.mts` declaration file, in some scenarios, the full extension of the module import path is needed to load correctly.
+When loading a module with `moduleResolution: 'nodenext'`, the import path needs to include the full file extension. Rslib will automatically add the corresponding file extension based on the actual JavaScript output file.
 
 ```ts
 import { foo } from './foo'; // source code of './src/bar.ts' ↓