Fix barrel optimization to ignore layers

packages/next/src/build/webpack/loaders/next-barrel-loader.ts

@@ -104,7 +104,6 @@ const barrelTransformMappingCache = new Map<
 >()
 
 async function getBarrelMapping(
-  layer: string | null | undefined,
   resourcePath: string,
   swcCacheDir: string,
   resolve: (context: string, request: string) => Promise<string>,
@@ -135,9 +134,6 @@ async function getBarrelMapping(
         optimizeBarrelExports: {
           wildcard: isWildcard,
         },
-        serverComponents: {
-          isReactServerLayer: layer === WEBPACK_LAYERS.reactServerComponents,
-        },
         jsc: {
           parser: {
             syntax: isTypeScript ? 'typescript' : 'ecmascript',
@@ -249,7 +245,6 @@ const NextBarrelLoader = async function (
   })
 
   const mapping = await getBarrelMapping(
-    this._module?.layer,
     this.resourcePath,
     swcCacheDir,
     resolve,

test/development/basic/barrel-optimization/barrel-optimization.test.ts

@@ -28,6 +28,9 @@ createNextDescribe(
       '@heroicons/react': '2.0.18',
       '@visx/visx': '3.3.0',
       'recursive-barrel': '1.0.0',
+      '@mui/material': '5.14.19',
+      '@emotion/styled': '11.11.0',
+      '@emotion/react': '11.11.1',
     },
   },
   ({ next }) => {
@@ -127,6 +130,30 @@ createNextDescribe(
       expect(html).toContain('<linearGradient')
     })
 
+    it('should support MUI', async () => {
+      let logs = ''
+      next.on('stdout', (log) => {
+        logs += log
+      })
+
+      // Ensure that MUI is working
+      const html = await next.render('/mui')
+      expect(html).toContain('test_mui')
+
+      const modules = [
+        ...logs.matchAll(
+          /Compiled (\/[\w-]+)*\s*in \d+(\.\d+)?(s|ms) \((\d+) modules\)/g
+        ),
+      ]
+
+      expect(modules.length).toBeGreaterThanOrEqual(1)
+      for (const [, , , , moduleCount] of modules) {
+        // Ensure that the number of modules is less than 1000 - otherwise we're
+        // importing the entire library.
+        expect(parseInt(moduleCount)).toBeLessThan(1000)
+      }
+    })
+
     it('should not break "use client" directive in optimized packages', async () => {
       const html = await next.render('/client')
       expect(html).toContain('this is a client component')

test/development/basic/barrel-optimization/fixture/app/mui/page.js

@@ -0,0 +1,5 @@
+import { Button } from '@mui/material'
+
+export default function Page() {
+  return <Button>test_mui</Button>
+}