fix(resolve): support resolving TS files by JS extension specifiers in JS files

packages/vite/src/node/optimizer/scan.ts

@@ -105,11 +105,6 @@ export function devToScanEnvironment(
   } as unknown as ScanEnvironment
 }
 
-type ResolveIdOptions = Omit<
-  Parameters<EnvironmentPluginContainer['resolveId']>[2],
-  'environment'
->
-
 const debug = createDebugger('vite:deps')
 
 const htmlTypesRE = /\.(html|vue|svelte|astro|imba)$/
@@ -383,27 +378,19 @@ function esbuildScanPlugin(
   async function resolveId(
     id: string,
     importer?: string,
-    options?: ResolveIdOptions,
   ): Promise<PartialResolvedId | null> {
     return environment.pluginContainer.resolveId(
       id,
       importer && normalizePath(importer),
-      {
-        ...options,
-        scan: true,
-      },
+      { scan: true },
     )
   }
-  const resolve = async (
-    id: string,
-    importer?: string,
-    options?: ResolveIdOptions,
-  ) => {
+  const resolve = async (id: string, importer?: string) => {
     const key = id + (importer && path.dirname(importer))
     if (seen.has(key)) {
       return seen.get(key)
     }
-    const resolved = await resolveId(id, importer, options)
+    const resolved = await resolveId(id, importer)
     const res = resolved?.id
     seen.set(key, res)
     return res
@@ -633,18 +620,14 @@ function esbuildScanPlugin(
           // avoid matching windows volume
           filter: /^[\w@][^:]/,
         },
-        async ({ path: id, importer, pluginData }) => {
+        async ({ path: id, importer }) => {
           if (moduleListContains(exclude, id)) {
             return externalUnlessEntry({ path: id })
           }
           if (depImports[id]) {
             return externalUnlessEntry({ path: id })
           }
-          const resolved = await resolve(id, importer, {
-            custom: {
-              depScan: { loader: pluginData?.htmlType?.loader },
-            },
-          })
+          const resolved = await resolve(id, importer)
           if (resolved) {
             if (shouldExternalizeDep(resolved, id)) {
               return externalUnlessEntry({ path: id })
@@ -706,13 +689,9 @@ function esbuildScanPlugin(
         {
           filter: /.*/,
         },
-        async ({ path: id, importer, pluginData }) => {
+        async ({ path: id, importer }) => {
           // use vite resolver to support urls and omitted extensions
-          const resolved = await resolve(id, importer, {
-            custom: {
-              depScan: { loader: pluginData?.htmlType?.loader },
-            },
-          })
+          const resolved = await resolve(id, importer)
           if (resolved) {
             if (
               shouldExternalizeDep(resolved, id) ||

packages/vite/src/node/plugins/resolve.ts

@@ -28,7 +28,6 @@ import {
   isNonDriveRelativeAbsolutePath,
   isObject,
   isOptimizable,
-  isTsRequest,
   normalizePath,
   safeRealpathSync,
   tryStatSync,
@@ -124,10 +123,7 @@ interface ResolvePluginOptions {
   tryPrefix?: string
   preferRelative?: boolean
   isRequire?: boolean
-  // #3040
-  // when the importer is a ts module,
-  // if the specifier requests a non-existent `.js/jsx/mjs/cjs` file,
-  // should also try import from `.ts/tsx/mts/cts` source file as fallback.
+  /** @deprecated */
   isFromTsImporter?: boolean
   // True when resolving during the scan phase to discover dependencies
   scan?: boolean
@@ -243,18 +239,6 @@ export function resolvePlugin(
         }
       }
 
-      if (importer) {
-        if (
-          isTsRequest(importer) ||
-          resolveOpts.custom?.depScan?.loader?.startsWith('ts')
-        ) {
-          options.isFromTsImporter = true
-        } else {
-          const moduleLang = this.getModuleInfo(importer)?.meta.vite?.lang
-          options.isFromTsImporter = moduleLang && isTsRequest(`.${moduleLang}`)
-        }
-      }
-
       let res: string | PartialResolvedId | undefined
 
       // resolve pre-bundled deps requests, these could be resolved by
@@ -598,7 +582,7 @@ function tryCleanFsResolve(
   let res: string | undefined
 
   // If path.dirname is a valid directory, try extensions and ts resolution logic
-  const possibleJsToTs = options.isFromTsImporter && isPossibleTsOutput(file)
+  const possibleJsToTs = isPossibleTsOutput(file)
   if (possibleJsToTs || options.extensions.length || tryPrefix) {
     const dirPath = path.dirname(file)
     if (isDirectory(dirPath)) {

packages/vite/src/node/utils.ts

@@ -295,9 +295,6 @@ export const isJSRequest = (url: string): boolean => {
   return false
 }
 
-const knownTsRE = /\.(?:ts|mts|cts|tsx)(?:$|\?)/
-export const isTsRequest = (url: string): boolean => knownTsRE.test(url)
-
 const importQueryRE = /(\?|&)import=?(?:&|$)/
 const directRequestRE = /(\?|&)direct=?(?:&|$)/
 const internalPrefixes = [

playground/resolve/__tests__/resolve.spec.ts

@@ -111,6 +111,10 @@ test('a ts module can import another ts module using its corresponding js file n
   expect(await page.textContent('.ts-extension')).toMatch('[success]')
 })
 
+test('a js module can import another ts module using its corresponding js file name', async () => {
+  expect(await page.textContent('.js-ts-extension')).toMatch('[success]')
+})
+
 test('filename with dot', async () => {
   expect(await page.textContent('.dot')).toMatch('[success]')
 })

playground/resolve/index.html

@@ -113,6 +113,9 @@ <h2>
 </h2>
 <p class="cjs-extension">fail</p>
 
+<h2>A js module can import TS modules using its corresponding js file name</h2>
+<p class="js-ts-extension">fail</p>
+
 <h2>Resolve file name containing dot</h2>
 <p class="dot">fail</p>
 
@@ -301,6 +304,9 @@ <h2>resolve non normalized absolute path</h2>
   import { msgMjs as tsMjsExtensionWithQueryMsg } from './ts-extension?query=1'
   text('.mjs-extension-with-query', tsMjsExtensionWithQueryMsg)
 
+  import { msg as jsTsExtensionMsg } from './ts-extension/index-js.js'
+  text('.js-ts-extension', jsTsExtensionMsg)
+
   // filename with dot
   import { bar } from './util/bar.util'
   text('.dot', bar())

playground/resolve/ts-extension/index-js.js

@@ -0,0 +1,10 @@
+import { msg as msgJs } from './hello.js'
+import { msgJsx } from './hellojsx.jsx'
+import { msgTsx } from './hellotsx.js'
+import { msgCjs } from './hellocjs.cjs'
+import { msgMjs } from './hellomjs.mjs'
+
+export const msg =
+  msgJs && msgJsx && msgTsx && msgCjs && msgMjs
+    ? '[success] use .js / .jsx / .cjs / .mjs extension to import a TS modules'
+    : '[fail]'