vercel · mischnic · Dec 1, 2025 · Nov 27, 2025 · Nov 27, 2025 · Nov 27, 2025
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
@@ -910,10 +910,12 @@ jobs:
         export IS_WEBPACK_TEST=1
 
         BROWSER_NAME=firefox node run-tests.js \
-          test/production/pages-dir/production/test/index.test.ts
+          test/production/pages-dir/production/test/index.test.ts \
+          test/production/chunk-load-failure/chunk-load-failure.test.ts
 
         NEXT_TEST_MODE=start BROWSER_NAME=safari node run-tests.js \
           test/production/pages-dir/production/test/index.test.ts \
+          test/production/chunk-load-failure/chunk-load-failure.test.ts \
           test/e2e/basepath/basepath.test.ts \
           test/e2e/basepath/error-pages.test.ts
 

diff --git a/test/production/chunk-load-failure/app/dynamic/async.ts b/test/production/chunk-load-failure/app/dynamic/async.ts
@@ -0,0 +1,3 @@
+export default function Async() {
+  return 'this is a lazy loaded async component'
+}
diff --git a/test/production/chunk-load-failure/app/dynamic/page.tsx b/test/production/chunk-load-failure/app/dynamic/page.tsx
@@ -0,0 +1,16 @@
+'use client'
+
+import dynamic from 'next/dynamic'
+import { Suspense } from 'react'
+
+const Async = dynamic(() => import('./async'), { ssr: false })
+
+export default function Page() {
+  return (
+    <>
+      <Suspense fallback={<div>Loading...</div>}>
+        <Async />
+      </Suspense>
+    </>
+  )
+}
diff --git a/test/production/chunk-load-failure/app/layout.tsx b/test/production/chunk-load-failure/app/layout.tsx
@@ -0,0 +1,8 @@
+export default function Layout({ children }) {
+  return (
+    <html lang="en">
+      <head />
+      <body>{children}</body>
+    </html>
+  )
+}
diff --git a/test/production/chunk-load-failure/app/other/page.tsx b/test/production/chunk-load-failure/app/other/page.tsx
@@ -0,0 +1,5 @@
+'use client'
+
+export default function Page() {
+  return <>this is other</>
+}
diff --git a/test/production/chunk-load-failure/chunk-load-failure.test.ts b/test/production/chunk-load-failure/chunk-load-failure.test.ts
@@ -0,0 +1,106 @@
+import { nextTestSetup } from 'e2e-utils'
+import { recursiveReadDir } from 'next/dist/lib/recursive-readdir'
+import path from 'path'
+import fs from 'fs'
+import { retry } from 'next-test-utils'
+
+describe('chunk-load-failure', () => {
+  const { next } = nextTestSetup({
+    files: __dirname,
+  })
+
+  async function getNextDynamicChunk() {
+    const chunksPath = path.join(next.testDir, '.next/static/')
+    const browserChunks = await recursiveReadDir(chunksPath, {
+      pathnameFilter: (f) => /\.js$/.test(f),
+    })
+    let nextDynamicChunks = browserChunks.filter((f) =>
+      fs
+        .readFileSync(path.join(chunksPath, f), 'utf8')
+        .includes('this is a lazy loaded async component')
+    )
+    expect(nextDynamicChunks).toHaveLength(1)
+
+    return nextDynamicChunks[0]
+  }
+
+  it('should report async chunk load failures', async () => {
+    let nextDynamicChunk = await getNextDynamicChunk()
+
+    let pageError: Error | undefined
+    const browser = await next.browser('/dynamic', {
+      beforePageLoad(page) {
+        page.route('**/' + nextDynamicChunk, async (route) => {
+          await route.abort('connectionreset')
+        })
+        page.on('pageerror', (error: Error) => {
+          pageError = error
+        })
+      },
+    })
+
+    await retry(async () => {
+      const body = await browser.elementByCss('body')
+      expect(await body.text()).toMatch(
+        /Application error: a client-side exception has occurred while loading/
+      )
+    })
+
+    expect(pageError).toBeDefined()
+    expect(pageError.name).toBe('ChunkLoadError')
+    if (process.env.IS_TURBOPACK_TEST) {
+      expect(pageError.message).toStartWith(
+        'Failed to load chunk /_next/static/' + nextDynamicChunk
+      )
+    } else {
+      expect(pageError.message).toMatch(/^Loading chunk \S+ failed./)
+      expect(pageError.message).toContain('/_next/static/' + nextDynamicChunk)
+    }
+  })
+
+  it('should report aborted chunks when navigating away', async () => {
+    let nextDynamicChunk = await getNextDynamicChunk()
+
+    let resolve
+    try {
+      const browser = await next.browser('/dynamic', {
+        beforePageLoad(page) {
+          page.route('**/' + nextDynamicChunk, async (route) => {
+            // deterministically ensure that the async chunk is still loading during the navigation
+            await new Promise((r) => {
+              resolve = r
+            })
+          })
+          page.on('pageerror', (error: Error) => {
+            console.log('pageerror', error)
+          })
+        },
+      })
+
+      await browser.get(next.url + '/other')
+
+      let body = await browser.elementByCss('body')
+      expect(await body.text()).toMatch('this is other')
+
+      const browserLogs = (await browser.log()).filter(
+        (m) => m.source === 'warning' || m.source === 'error'
+      )
+
+      if (process.env.BROWSER_NAME === 'firefox') {
+        expect(browserLogs).toContainEqual(
+          expect.objectContaining({
+            message: expect.stringContaining(
+              'Loading failed for the <script> with source'
+            ),
+          })
+        )
+      } else {
+        // Chrome and Safari doesn't show any errors or warnings here
+        expect(browserLogs).toBeEmpty()
+      }
+    } finally {
+      // prevent hanging
+      resolve?.()
+    }
+  })
+})
diff --git a/test/production/chunk-load-failure/next.config.mjs b/test/production/chunk-load-failure/next.config.mjs
@@ -0,0 +1,4 @@
+/** @type {import('next').NextConfig} */
+const nextConfig = {}
+
+export default nextConfig
diff --git a/turbopack/crates/turbopack-ecmascript-runtime/js/src/browser/runtime/base/runtime-base.ts b/turbopack/crates/turbopack-ecmascript-runtime/js/src/browser/runtime/base/runtime-base.ts
@@ -250,7 +250,7 @@ function loadChunkByUrlInternal(
       thenable,
       loadedChunk
     )
-    entry = thenable.then(resolve).catch((error) => {
+    entry = thenable.then(resolve).catch((cause) => {
       let loadReason: string
       switch (sourceType) {
         case SourceType.Runtime:
@@ -268,16 +268,14 @@ function loadChunkByUrlInternal(
             (sourceType) => `Unknown source type: ${sourceType}`
           )
       }
-      throw new Error(
+      let error = new Error(
         `Failed to load chunk ${chunkUrl} ${loadReason}${
-          error ? `: ${error}` : ''
+          cause ? `: ${cause}` : ''
         }`,
-        error
-          ? {
-              cause: error,
-            }
-          : undefined
+        cause ? { cause } : undefined
       )
+      error.name = 'ChunkLoadError'
+      throw error
     })
     instrumentedBackendLoadChunks.set(thenable, entry)
   }

diff --git a/turbopack/crates/turbopack-ecmascript-runtime/js/src/nodejs/runtime.ts b/turbopack/crates/turbopack-ecmascript-runtime/js/src/nodejs/runtime.ts
@@ -99,16 +99,16 @@ function loadRuntimeChunkPath(
     const chunkModules: CompressedModuleFactories = require(resolved)
     installCompressedModuleFactories(chunkModules, 0, moduleFactories)
     loadedChunks.add(chunkPath)
-  } catch (e) {
+  } catch (cause) {
     let errorMessage = `Failed to load chunk ${chunkPath}`
 
     if (sourcePath) {
       errorMessage += ` from runtime for chunk ${sourcePath}`
     }
 
-    throw new Error(errorMessage, {
-      cause: e,
-    })
+    const error = new Error(errorMessage, { cause })
+    error.name = 'ChunkLoadError'
+    throw error
   }
 }
 
@@ -133,15 +133,13 @@ function loadChunkAsync(
       const chunkModules: CompressedModuleFactories = require(resolved)
       installCompressedModuleFactories(chunkModules, 0, moduleFactories)
       entry = loadedChunk
-    } catch (e) {
+    } catch (cause) {
       const errorMessage = `Failed to load chunk ${chunkPath} from module ${this.m.id}`
+      const error = new Error(errorMessage, { cause })
+      error.name = 'ChunkLoadError'
 
       // Cache the failure promise, future requests will also get this same rejection
-      entry = Promise.reject(
-        new Error(errorMessage, {
-          cause: e,
-        })
-      )
+      entry = Promise.reject(error)
-      entry = Promise.reject(error)
+      entry = Promise.resolve().then(() => { throw error })
-      entry = Promise.reject(error)
+      entry = Promise.resolve().then(() => { throw error })
     }
     chunkCache.set(chunkPath, entry)
   }

diff --git a/...aaf3a_crates_turbopack-tests_tests_snapshot_debug-ids_browser_input_index_0151fefb.js.map b/...aaf3a_crates_turbopack-tests_tests_snapshot_debug-ids_browser_input_index_0151fefb.js.map
diff --git a/...put/ba425_crates_turbopack-tests_tests_snapshot_debug-ids_browser_input_index_0151fefb.js b/...put/ba425_crates_turbopack-tests_tests_snapshot_debug-ids_browser_input_index_0151fefb.js
diff --git a/turbopack/crates/turbopack-tests/tests/snapshot/debug-ids/node/output/[turbopack]_runtime.js b/turbopack/crates/turbopack-tests/tests/snapshot/debug-ids/node/output/[turbopack]_runtime.js
diff --git a/...ck/crates/turbopack-tests/tests/snapshot/debug-ids/node/output/[turbopack]_runtime.js.map b/...ck/crates/turbopack-tests/tests/snapshot/debug-ids/node/output/[turbopack]_runtime.js.map
diff --git a/...urbopack-tests/tests/snapshot/runtime/default_build_runtime/output/[turbopack]_runtime.js b/...urbopack-tests/tests/snapshot/runtime/default_build_runtime/output/[turbopack]_runtime.js
diff --git a/...pack-tests/tests/snapshot/runtime/default_build_runtime/output/[turbopack]_runtime.js.map b/...pack-tests/tests/snapshot/runtime/default_build_runtime/output/[turbopack]_runtime.js.map
diff --git a/.../5c1d0_turbopack-tests_tests_snapshot_runtime_default_dev_runtime_input_index_c0f7e0b0.js b/.../5c1d0_turbopack-tests_tests_snapshot_runtime_default_dev_runtime_input_index_c0f7e0b0.js
diff --git a/...ce_turbopack-tests_tests_snapshot_runtime_default_dev_runtime_input_index_c0f7e0b0.js.map b/...ce_turbopack-tests_tests_snapshot_runtime_default_dev_runtime_input_index_c0f7e0b0.js.map
diff --git a/...ut/5c1d0_turbopack-tests_tests_snapshot_swc_transforms_preset_env_input_index_5aaf1327.js b/...ut/5c1d0_turbopack-tests_tests_snapshot_swc_transforms_preset_env_input_index_5aaf1327.js
diff --git a/...80ce_turbopack-tests_tests_snapshot_swc_transforms_preset_env_input_index_5aaf1327.js.map b/...80ce_turbopack-tests_tests_snapshot_swc_transforms_preset_env_input_index_5aaf1327.js.map