fix(ssr): apply alias to resolvable dependencies during dev (#15602)

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

@@ -68,6 +68,7 @@ import { isCSSRequest, isDirectCSSRequest } from './css'
 import { browserExternalId } from './resolve'
 import { serializeDefine } from './define'
 import { WORKER_FILE_ID } from './worker'
+import { getAliasPatternMatcher } from './preAlias'
 
 const debug = createDebugger('vite:import-analysis')
 
@@ -172,6 +173,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
   const fsUtils = getFsUtils(config)
   const clientPublicPath = path.posix.join(base, CLIENT_PUBLIC_PATH)
   const enablePartialAccept = config.experimental?.hmrPartialAccept
+  const matchAlias = getAliasPatternMatcher(config.resolve.alias)
   let server: ViteDevServer
 
   let _env: string | undefined
@@ -487,7 +489,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
               return
             }
             // skip ssr external
-            if (ssr) {
+            if (ssr && !matchAlias(specifier)) {
               if (shouldExternalizeForSSR(specifier, importer, config)) {
                 return
               }

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

@@ -128,3 +128,11 @@ function getAliasPatterns(
   }
   return Object.entries(entries).map(([find]) => find)
 }
+
+export function getAliasPatternMatcher(
+  entries: (AliasOptions | undefined) & Alias[],
+): (importee: string) => boolean {
+  const patterns = getAliasPatterns(entries)
+  return (importee: string) =>
+    patterns.some((pattern) => matches(pattern, importee))
+}

playground/ssr-alias/__tests__/ssr-alias.spec.ts

@@ -0,0 +1,20 @@
+import { expect, test } from 'vitest'
+import { isServe, testDir, viteServer } from '~utils'
+
+test.runIf(isServe)('dev', async () => {
+  const mod = await viteServer.ssrLoadModule('/src/main.js')
+  expect(mod.default).toEqual({
+    dep: 'ok',
+    nonDep: 'ok',
+    builtin: 'ok',
+  })
+})
+
+test.runIf(!isServe)('build', async () => {
+  const mod = await import(`${testDir}/dist/main.js`)
+  expect(mod.default).toEqual({
+    dep: 'ok',
+    nonDep: 'ok',
+    builtin: 'ok',
+  })
+})

playground/ssr-alias/alias-original/index.js

@@ -0,0 +1 @@
+export default 'original'

playground/ssr-alias/alias-original/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@vitejs/test-alias-original",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    ".": "./index.js"
+  }
+}

playground/ssr-alias/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "@vitejs/test-ssr-html",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "build": "vite build"
+  },
+  "dependencies": {
+    "@vitejs/test-alias-original": "file:./alias-original"
+  }
+}

playground/ssr-alias/src/alias-process.js

@@ -0,0 +1,3 @@
+export default {
+  env: { __TEST_ALIAS__: 'ok' },
+}

playground/ssr-alias/src/alias-replaced.js

@@ -0,0 +1 @@
+export default 'ok'

playground/ssr-alias/src/main.js

@@ -0,0 +1,9 @@
+import process from 'node:process'
+import dep from '@vitejs/test-alias-original'
+import nonDep from '@vitejs/test-alias-non-dep'
+
+export default {
+  dep,
+  nonDep,
+  builtin: process.env['__TEST_ALIAS__'],
+}

playground/ssr-alias/vite.config.js

@@ -0,0 +1,14 @@
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  build: {
+    ssr: './src/main.js',
+  },
+  resolve: {
+    alias: {
+      '@vitejs/test-alias-original': '/src/alias-replaced.js',
+      '@vitejs/test-alias-non-dep': '/src/alias-replaced.js',
+      'node:process': '/src/alias-process.js',
+    },
+  },
+})