fix: __vite__mapDeps code injection

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

@@ -507,13 +507,11 @@ function __vite__mapDeps(indexes) {
   return indexes.map((i) => __vite__mapDeps.viteFileDeps[i])
 }\n`
 
-          // inject extra code before sourcemap comment
-          const mapFileCommentMatch =
-            convertSourceMap.mapFileCommentRegex.exec(code)
-          if (mapFileCommentMatch) {
-            s.appendRight(mapFileCommentMatch.index, mapDepsCode)
+          // inject extra code at the top or next line of hashbang
+          if (code.startsWith('#!')) {
+            s.prependLeft(code.indexOf('\n') + 1, mapDepsCode)
           } else {
-            s.append(mapDepsCode)
+            s.prepend(mapDepsCode)
           }
 
           // there may still be markers due to inlined dynamic imports, remove

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

@@ -137,7 +137,7 @@ describe.runIf(isBuild)('build tests', () => {
     const map = findAssetFile(/after-preload-dynamic.*\.js\.map/)
     expect(formatSourcemapForSnapshot(JSON.parse(map))).toMatchInlineSnapshot(`
       {
-        "mappings": "i3BAAA,OAAO,2BAAuB,EAAC,wBAE/B,QAAQ,IAAI,uBAAuB",
+        "mappings": ";;;;;;i3BAAA,OAAO,2BAAuB,EAAC,wBAE/B,QAAQ,IAAI,uBAAuB",
         "sources": [
           "../../after-preload-dynamic.js",
         ],
@@ -150,10 +150,10 @@ describe.runIf(isBuild)('build tests', () => {
         "version": 3,
       }
     `)
-    //
+    // verify sourcemap comment is preserved at the last line
     const js = findAssetFile(/after-preload-dynamic.*\.js$/)
-    expect(js.trim().split('\n').at(-1)).toMatch(
-      /^\/\/# sourceMappingURL=after-preload-dynamic.*\.js\.map$/,
+    expect(js).toMatch(
+      /\n\/\/# sourceMappingURL=after-preload-dynamic.*\.js\.map\n$/,
     )
   })
 })

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

@@ -0,0 +1,5 @@
+// hashbang is injected via rollupOptions.output.banner
+
+import('./dynamic/dynamic-foo')
+
+console.log('after preload dynamic hashbang')

playground/js-sourcemap/index.html

@@ -6,5 +6,6 @@ <h1>JS Sourcemap</h1>
 <script type="module" src="./foo.js"></script>
 <script type="module" src="./bar.ts"></script>
 <script type="module" src="./after-preload-dynamic.js"></script>
+<script type="module" src="./after-preload-dynamic-hashbang.js"></script>
 <script type="module" src="./with-multiline-import.ts"></script>
 <script type="module" src="./zoo.js"></script>

playground/js-sourcemap/vite.config.js

@@ -12,9 +12,17 @@ export default defineConfig({
     rollupOptions: {
       output: {
         manualChunks(name) {
-          if (name.includes('after-preload-dynamic')) {
+          if (name.endsWith('after-preload-dynamic.js')) {
             return 'after-preload-dynamic'
           }
+          if (name.endsWith('after-preload-dynamic-hashbang.js')) {
+            return 'after-preload-dynamic-hashbang'
+          }
+        },
+        banner(chunk) {
+          if (chunk.name.endsWith('after-preload-dynamic-hashbang')) {
+            return '#!/usr/bin/env node'
+          }
         },
       },
     },