Improve Server Reference ID DCE tests (#70191)

This PR improves the integration test of dead code elimination of Server
Reference IDs in the client bundle, to cover:
- Barrel files (re-exports and nested imports)
- Side effects in server boundary and intermediate modules
- SWC compression

test/production/app-dir/actions-tree-shaking/client-actions-tree-shaking/app/actions.js

@@ -1,9 +1,16 @@
 'use server'
 
+// Ensure side effects won't affect tree shaking and DCE
+console.log('This is a side effect')
+
 export async function foo() {
   console.log('This is action foo')
 }
 
 export async function bar() {
   console.log('This is action bar')
 }
+
+export async function baz() {
+  console.log('This is action baz')
+}

test/production/app-dir/actions-tree-shaking/client-actions-tree-shaking/app/route-3/barrel.js

@@ -0,0 +1,6 @@
+import { baz } from '../actions'
+
+// Ensure side effects won't affect tree shaking and DCE
+console.log(1)
+
+export { baz }

test/production/app-dir/actions-tree-shaking/client-actions-tree-shaking/app/route-3/page.js

@@ -0,0 +1,12 @@
+'use client'
+
+import { baz } from './barrel'
+
+export default function Page() {
+  // Test DCE
+  if (1 + 1 === 3) {
+    baz()
+  }
+
+  return <div>hi</div>
+}

test/production/app-dir/actions-tree-shaking/client-actions-tree-shaking/client-actions-tree-shaking.test.ts

@@ -37,6 +37,9 @@ describe('app-dir - client-actions-tree-shaking', () => {
     const route2Files = await fs.readdir(
       join(appDir, '.next/static/chunks/app/route-2')
     )
+    const route3Files = await fs.readdir(
+      join(appDir, '.next/static/chunks/app/route-3')
+    )
 
     const route1Bundle = await fs.readFile(
       join(
@@ -52,14 +55,25 @@ describe('app-dir - client-actions-tree-shaking', () => {
         route2Files.find((file) => file.endsWith('.js'))
       )
     )
+    const route3Bundle = await fs.readFile(
+      join(
+        appDir,
+        '.next/static/chunks/app/route-3',
+        route3Files.find((file) => file.endsWith('.js'))
+      )
+    )
 
     const bundle1Ids = getServerReferenceIdsFromBundle(route1Bundle.toString())
     const bundle2Ids = getServerReferenceIdsFromBundle(route2Bundle.toString())
+    const bundle3Ids = getServerReferenceIdsFromBundle(route3Bundle.toString())
 
-    // Each should only have one ID.
+    // Bundle 1 and 2 should only have one ID.
     expect(bundle1Ids).toHaveLength(1)
     expect(bundle2Ids).toHaveLength(1)
     expect(bundle1Ids[0]).not.toEqual(bundle2Ids[0])
+
+    // Bundle 3 should have no IDs.
+    expect(bundle3Ids).toHaveLength(0)
   })
 
   // Test the application