fix(ssr): remove pure CSS dynamic import (#17371)

Author: sapphi-red

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

@@ -318,7 +318,64 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
     },
 
     generateBundle({ format }, bundle) {
-      if (format !== 'es' || ssr || isWorker) {
+      if (format !== 'es') {
+        return
+      }
+
+      if (ssr || isWorker) {
+        const removedPureCssFiles = removedPureCssFilesCache.get(config)
+        if (removedPureCssFiles && removedPureCssFiles.size > 0) {
+          for (const file in bundle) {
+            const chunk = bundle[file]
+            if (chunk.type === 'chunk' && chunk.code.includes('import')) {
+              const code = chunk.code
+              let imports!: ImportSpecifier[]
+              try {
+                imports = parseImports(code)[0].filter((i) => i.d > -1)
+              } catch (e: any) {
+                const loc = numberToPos(code, e.idx)
+                this.error({
+                  name: e.name,
+                  message: e.message,
+                  stack: e.stack,
+                  cause: e.cause,
+                  pos: e.idx,
+                  loc: { ...loc, file: chunk.fileName },
+                  frame: generateCodeFrame(code, loc),
+                })
+              }
+
+              for (const imp of imports) {
+                const {
+                  n: name,
+                  s: start,
+                  e: end,
+                  ss: expStart,
+                  se: expEnd,
+                } = imp
+                let url = name
+                if (!url) {
+                  const rawUrl = code.slice(start, end)
+                  if (rawUrl[0] === `"` && rawUrl[rawUrl.length - 1] === `"`)
+                    url = rawUrl.slice(1, -1)
+                }
+                if (!url) continue
+
+                const normalizedFile = path.posix.join(
+                  path.posix.dirname(chunk.fileName),
+                  url,
+                )
+                if (removedPureCssFiles.has(normalizedFile)) {
+                  // remove with Promise.resolve({}) while preserving source map location
+                  chunk.code =
+                    chunk.code.slice(0, expStart) +
+                    `Promise.resolve({${''.padEnd(expEnd - expStart - 19, ' ')}})` +
+                    chunk.code.slice(expEnd)
+                }
+              }
+            }
+          }
+        }
         return
       }