fix: output combined sourcemap in importAnalysisBuild plugin

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

@@ -5,6 +5,7 @@ import { init, parse as parseImports } from 'es-module-lexer'
 import type { OutputChunk, SourceMap } from 'rollup'
 import colors from 'picocolors'
 import type { RawSourceMap } from '@ampproject/remapping'
+import convertSourceMap from 'convert-source-map'
 import {
   bareImportRE,
   cleanUrl,
@@ -608,6 +609,19 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
               ) as SourceMap
               map.toUrl = () => genSourceMapUrl(map)
               chunk.map = map
+
+              if (config.build.sourcemap === 'inline') {
+                chunk.code = chunk.code.replace(
+                  convertSourceMap.mapFileCommentRegex,
+                  '',
+                )
+                chunk.code += `\n//# sourceMappingURL=${genSourceMapUrl(map)}`
+              } else if (config.build.sourcemap) {
+                const mapAsset = bundle[chunk.fileName + '.map']
+                if (mapAsset && mapAsset.type === 'asset') {
+                  mapAsset.source = map.toString()
+                }
+              }
             }
           }
         }

playground/js-sourcemap/__tests__/js-sourcemap.spec.ts

@@ -1,7 +1,8 @@
 import { URL } from 'node:url'
-import { expect, test } from 'vitest'
+import { describe, expect, test } from 'vitest'
 import {
   extractSourcemap,
+  findAssetFile,
   formatSourcemapForSnapshot,
   isBuild,
   page,
@@ -40,14 +41,31 @@ if (!isBuild) {
       expect(log).not.toMatch(/Sourcemap for .+ points to missing source files/)
     })
   })
-} else {
-  test('this file only includes test for serve', () => {
-    expect(true).toBe(true)
-  })
 }
 
-test.runIf(isBuild)('should not output sourcemap warning (#4939)', () => {
-  serverLogs.forEach((log) => {
-    expect(log).not.toMatch('Sourcemap is likely to be incorrect')
+describe.runIf(isBuild)('build tests', () => {
+  test('should not output sourcemap warning (#4939)', () => {
+    serverLogs.forEach((log) => {
+      expect(log).not.toMatch('Sourcemap is likely to be incorrect')
+    })
+  })
+
+  test('sourcemap is correct when preload information is injected', async () => {
+    const map = findAssetFile(/after-preload-dynamic.*\.js\.map/)
+    expect(formatSourcemapForSnapshot(JSON.parse(map))).toMatchInlineSnapshot(`
+      {
+        "mappings": "stBAAAA,aAAO,2BAAuB,EAAC,sEAE/B,QAAQ,IAAI,uBAAuB",
+        "sources": [
+          "../../after-preload-dynamic.js",
+        ],
+        "sourcesContent": [
+          "import('./dynamic/dynamic-foo')
+
+      console.log('after preload dynamic')
+      ",
+        ],
+        "version": 3,
+      }
+    `)
   })
 })

playground/js-sourcemap/after-preload-dynamic.js

@@ -0,0 +1,3 @@
+import('./dynamic/dynamic-foo')
+
+console.log('after preload dynamic')

playground/js-sourcemap/dynamic/dynamic-foo.css

@@ -0,0 +1,3 @@
+.dynamic-foo {
+  color: red;
+}

playground/js-sourcemap/dynamic/dynamic-foo.js

@@ -0,0 +1,3 @@
+import './dynamic-foo.css'
+
+console.log('dynamic/dynamic-foo')

playground/js-sourcemap/index.html

@@ -1,6 +1,8 @@
 <div class="wrapper">
   <h1>JS Sourcemap</h1>
+  <div class="dynamic-foo">dynamic</div>
 </div>
 
 <script type="module" src="./foo.js"></script>
 <script type="module" src="./bar.ts"></script>
+<script type="module" src="./after-preload-dynamic.js"></script>

playground/js-sourcemap/vite.config.js

@@ -3,5 +3,14 @@ import { defineConfig } from 'vite'
 export default defineConfig({
   build: {
     sourcemap: true,
+    rollupOptions: {
+      output: {
+        manualChunks(name) {
+          if (name.includes('after-preload-dynamic')) {
+            return 'after-preload-dynamic'
+          }
+        },
+      },
+    },
   },
 })