fix(sourcemap): preserve original sourcesContent

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

@@ -439,7 +439,7 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
         const getContentWithSourcemap = async (content: string) => {
           if (config.css?.devSourcemap) {
             const sourcemap = this.getCombinedSourcemap()
-            if (sourcemap.mappings && !sourcemap.sourcesContent) {
+            if (sourcemap.mappings) {
               await injectSourcesContent(sourcemap, cleanUrl(id), config.logger)
             }
             return getCodeWithSourcemap('css', content, sourcemap)

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

@@ -652,11 +652,10 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
                 source: chunk.fileName,
                 hires: true,
               })
-              const map = combineSourcemaps(
-                chunk.fileName,
-                [nextMap as RawSourceMap, chunk.map as RawSourceMap],
-                false,
-              ) as SourceMap
+              const map = combineSourcemaps(chunk.fileName, [
+                nextMap as RawSourceMap,
+                chunk.map as RawSourceMap,
+              ]) as SourceMap
               map.toUrl = () => genSourceMapUrl(map)
               chunk.map = map
 

packages/vite/src/node/server/middlewares/indexHtml.ts

@@ -283,7 +283,7 @@ const devHtmlHook: IndexHtmlTransformHook = async (
       let content = ''
       if (result) {
         if (result.map) {
-          if (result.map.mappings && !result.map.sourcesContent) {
+          if (result.map.mappings) {
             await injectSourcesContent(
               result.map,
               proxyModulePath,

packages/vite/src/node/server/sourcemap.ts

@@ -33,22 +33,29 @@ export async function injectSourcesContent(
   } catch {}
 
   const missingSources: string[] = []
-  map.sourcesContent = await Promise.all(
-    map.sources.map((sourcePath) => {
+  const sourcesContent = map.sourcesContent || []
+  await Promise.all(
+    map.sources.map(async (sourcePath, index) => {
+      let content = null
       if (sourcePath && !virtualSourceRE.test(sourcePath)) {
         sourcePath = decodeURI(sourcePath)
         if (sourceRoot) {
           sourcePath = path.resolve(sourceRoot, sourcePath)
         }
-        return fsp.readFile(sourcePath, 'utf-8').catch(() => {
-          missingSources.push(sourcePath)
-          return null
-        })
+        // inject content from source file when sourcesContent is null
+        content =
+          sourcesContent[index] ??
+          (await fsp.readFile(sourcePath, 'utf-8').catch(() => {
+            missingSources.push(sourcePath)
+            return null
+          }))
       }
-      return null
+      sourcesContent[index] = content
     }),
   )
 
+  map.sourcesContent = sourcesContent
+
   // Use this command…
   //    DEBUG="vite:sourcemap" vite build
   // …to log the missing sources.

packages/vite/src/node/server/transformRequest.ts

@@ -285,7 +285,7 @@ async function loadAndTransform(
 
   if (map && mod.file) {
     map = (typeof map === 'string' ? JSON.parse(map) : map) as SourceMap
-    if (map.mappings && !map.sourcesContent) {
+    if (map.mappings) {
       await injectSourcesContent(map, mod.file, logger)
     }
 

packages/vite/src/node/ssr/ssrTransform.ts

@@ -276,18 +276,14 @@ async function ssrTransformScript(
 
   let map = s.generateMap({ hires: true })
   if (inMap && inMap.mappings && inMap.sources.length > 0) {
-    map = combineSourcemaps(
-      url,
-      [
-        {
-          ...map,
-          sources: inMap.sources,
-          sourcesContent: inMap.sourcesContent,
-        } as RawSourceMap,
-        inMap as RawSourceMap,
-      ],
-      false,
-    ) as SourceMap
+    map = combineSourcemaps(url, [
+      {
+        ...map,
+        sources: inMap.sources,
+        sourcesContent: inMap.sourcesContent,
+      } as RawSourceMap,
+      inMap as RawSourceMap,
+    ]) as SourceMap
   } else {
     map.sources = [path.basename(url)]
     // needs to use originalCode instead of code

packages/vite/src/node/utils.ts

@@ -748,7 +748,6 @@ const nullSourceMap: RawSourceMap = {
 export function combineSourcemaps(
   filename: string,
   sourcemapList: Array<DecodedSourceMap | RawSourceMap>,
-  excludeContent = true,
 ): RawSourceMap {
   if (
     sourcemapList.length === 0 ||
@@ -778,19 +777,15 @@ export function combineSourcemaps(
   const useArrayInterface =
     sourcemapList.slice(0, -1).find((m) => m.sources.length !== 1) === undefined
   if (useArrayInterface) {
-    map = remapping(sourcemapList, () => null, excludeContent)
+    map = remapping(sourcemapList, () => null)
   } else {
-    map = remapping(
-      sourcemapList[0],
-      function loader(sourcefile) {
-        if (sourcefile === escapedFilename && sourcemapList[mapIndex]) {
-          return sourcemapList[mapIndex++]
-        } else {
-          return null
-        }
-      },
-      excludeContent,
-    )
+    map = remapping(sourcemapList[0], function loader(sourcefile) {
+      if (sourcefile === escapedFilename && sourcemapList[mapIndex]) {
+        return sourcemapList[mapIndex++]
+      } else {
+        return null
+      }
+    })
   }
   if (!map.file) {
     delete map.file