feat: add customResolver option to resolve.alias (#5876)

docs/config/index.md

@@ -174,9 +174,9 @@ export default defineConfig(async ({ command, mode }) => {
 ### resolve.alias
 
 - **Type:**
-  `Record<string, string> | Array<{ find: string | RegExp, replacement: string }>`
+  `Record<string, string> | Array<{ find: string | RegExp, replacement: string, customResolver?: ResolverFunction | ResolverObject }>`
 
-  Will be passed to `@rollup/plugin-alias` as its [entries option](https://github.com/rollup/plugins/tree/master/packages/alias#entries). Can either be an object, or an array of `{ find, replacement }` pairs.
+  Will be passed to `@rollup/plugin-alias` as its [entries option](https://github.com/rollup/plugins/tree/master/packages/alias#entries). Can either be an object, or an array of `{ find, replacement, customResolver }` pairs.
 
   When aliasing to file system paths, always use absolute paths. Relative alias values will be used as-is and will not be resolved into file system paths.
 

packages/playground/alias/__tests__/alias.spec.ts

@@ -43,3 +43,9 @@ test('aliased module', async () => {
     '[success] aliased module'
   )
 })
+
+test('custom resolver', async () => {
+  expect(await page.textContent('.custom-resolver')).toMatch(
+    '[success] alias to custom-resolver path'
+  )
+})

packages/playground/alias/customResolver.js

@@ -0,0 +1 @@
+export const msg = `[success] alias to custom-resolver path`

packages/playground/alias/index.html

@@ -6,6 +6,7 @@ <h1>Alias</h1>
 <p class="dep"></p>
 <p class="from-script-src"></p>
 <p class="aliased-module"></p>
+<p class="custom-resolver"></p>
 
 <div class="optimized"></div>
 
@@ -15,6 +16,7 @@ <h1>Alias</h1>
   import { msg as regexMsg } from 'regex/test'
   import { msg as depMsg } from 'dep'
   import { msg as moduleMsg } from 'aliased-module/index.js'
+  import { msg as customResolverMsg } from 'custom-resolver'
 
   function text(el, text) {
     document.querySelector(el).textContent = text
@@ -25,6 +27,7 @@ <h1>Alias</h1>
   text('.regex', regexMsg + ' via regex')
   text('.dep', depMsg)
   text('.aliased-module', moduleMsg)
+  text('.custom-resolver', customResolverMsg)
 
   import { createApp } from 'vue'
   import { ref } from 'foo'

packages/playground/alias/vite.config.js

@@ -17,7 +17,14 @@ module.exports = {
       // aliasing an optimized dep
       { find: 'vue', replacement: 'vue/dist/vue.esm-bundler.js' },
       // aliasing one unoptimized dep to an optimized dep
-      { find: 'foo', replacement: 'vue' }
+      { find: 'foo', replacement: 'vue' },
+      {
+        find: 'custom-resolver',
+        replacement: path.resolve(__dirname, 'test.js'),
+        customResolver(id) {
+          return id.replace('test.js', 'customResolver.js')
+        }
+      }
     ]
   },
   build: {

packages/vite/src/node/config.ts

@@ -785,7 +785,11 @@ function normalizeAlias(o: AliasOptions): Alias[] {
 
 // https://github.com/vitejs/vite/issues/1363
 // work around https://github.com/rollup/plugins/issues/759
-function normalizeSingleAlias({ find, replacement }: Alias): Alias {
+function normalizeSingleAlias({
+  find,
+  replacement,
+  customResolver
+}: Alias): Alias {
   if (
     typeof find === 'string' &&
     find.endsWith('/') &&
@@ -794,7 +798,15 @@ function normalizeSingleAlias({ find, replacement }: Alias): Alias {
     find = find.slice(0, find.length - 1)
     replacement = replacement.slice(0, replacement.length - 1)
   }
-  return { find, replacement }
+
+  const alias: Alias = {
+    find,
+    replacement
+  }
+  if (customResolver) {
+    alias.customResolver = customResolver
+  }
+  return alias
 }
 
 export function sortUserPlugins(