fix: chunk split for dynamic import dep

packages/playground/dynamic-import/dep-a/index.js

@@ -0,0 +1 @@
+export default () => '[email protected]'

packages/playground/dynamic-import/dep-a/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "dep-a",
+  "version": "2.0.0",
+  "main": "index.js"
+}

packages/playground/dynamic-import/package.json

@@ -7,5 +7,8 @@
     "build": "vite build",
     "debug": "node --inspect-brk ../../vite/bin/vite",
     "preview": "vite preview"
+  },
+  "dependencies": {
+    "dep-a": "file:./dep-a"
   }
 }

packages/playground/dynamic-import/views/bar.js

@@ -1 +1,4 @@
+import getName from 'dep-a'
+console.log('bar' + getName())
+
 export const msg = 'Bar view'

packages/playground/dynamic-import/vite.config.js

@@ -2,6 +2,12 @@ const fs = require('fs')
 const path = require('path')
 
 module.exports = {
+  resolve: {
+    preserveSymlinks: true
+  },
+  optimizeDeps: {
+    exclude: ['dep-a']
+  },
   plugins: [
     {
       name: 'copy',

packages/vite/src/node/build.ts

@@ -647,12 +647,15 @@ function getPkgName(root: string) {
 function createMoveToVendorChunkFn(config: ResolvedConfig): GetManualChunk {
   const cache = new Map<string, boolean>()
   return (id, { getModuleInfo }) => {
-    if (
-      id.includes('node_modules') &&
-      !isCSSRequest(id) &&
-      staticImportedByEntry(id, getModuleInfo, cache)
-    ) {
-      return 'vendor'
+    if (id.includes('node_modules') && !isCSSRequest(id)) {
+      if (staticImportedByEntry(id, getModuleInfo, cache)) {
+        return 'vendor'
+      } else {
+        const entryName = resolveDynamicImportEntry(id, getModuleInfo, [])
+        if (entryName) {
+          return `async-vendor-${entryName}`
+        }
+      }
     }
   }
 }
@@ -693,6 +696,45 @@ function staticImportedByEntry(
   return someImporterIs
 }
 
+function resolveDynamicImportEntry(
+  id: string,
+  getModuleInfo: GetModuleInfo,
+  importStack: string[] = []
+): string | void {
+  const mod = getModuleInfo(id)
+  if (!mod || importStack.includes(id)) {
+    return
+  }
+
+  if (
+    mod.dynamicImporters.length > 0 &&
+    mod.dynamicImporters.some((importer) => !importer.includes('node_modules'))
+  ) {
+    if (id.includes('node_modules')) {
+      const dirs = id.split(path.sep)
+      const nodeModulesIndex = dirs.lastIndexOf('node_modules')
+      let packageName = dirs[nodeModulesIndex + 1]
+      if (packageName.startsWith('@')) {
+        packageName = path.join(packageName, dirs[nodeModulesIndex + 2])
+      }
+      return packageName
+    }
+    return path.basename(id, path.extname(id))
+  }
+
+  let entry
+  for (const importer of mod.importers) {
+    entry = resolveDynamicImportEntry(
+      importer,
+      getModuleInfo,
+      importStack.concat(id)
+    )
+    if (entry) {
+      return entry
+    }
+  }
+}
+
 export function resolveLibFilename(
   libOptions: LibraryOptions,
   format: ModuleFormat,