fix 404 export

huozhi · huozhi · commit 8912a2996a75 · 2025-08-10T23:51:23.000+02:00
diff --git a/packages/next/src/export/index.ts b/packages/next/src/export/index.ts
@@ -783,7 +783,39 @@ async function exportAppImpl(
       Object.keys(prerenderManifest.routes).map(async (unnormalizedRoute) => {
         // Special handling: map app /_not-found to 404.html (and 404/index.html when trailingSlash)
         if (unnormalizedRoute === '/_not-found') {
-          return
+          const { srcRoute } = prerenderManifest!.routes[unnormalizedRoute]
+          const appPageName = mapAppRouteToPage.get(srcRoute || '')
+          const pageName = appPageName || srcRoute || unnormalizedRoute
+          const isAppPath = Boolean(appPageName)
+          const route = normalizePagePath(unnormalizedRoute)
+
+          const pagePath = getPagePath(pageName, distDir, undefined, isAppPath)
+          const distPagesDir = join(
+            pagePath,
+            pageName
+              .slice(1)
+              .split('/')
+              .map(() => '..')
+              .join('/')
+          )
+
+          const orig = join(distPagesDir, route)
+          const htmlSrc = `${orig}.html`
+
+          // write 404.html at root
+          const htmlDest404 = join(outDir, '404.html')
+          await fs.mkdir(dirname(htmlDest404), { recursive: true })
+          await fs.copyFile(htmlSrc, htmlDest404)
+
+          // When trailingSlash, also write 404/index.html
+          if (subFolders) {
+            const htmlDest404Index = join(outDir, '404', 'index.html')
+            await fs.mkdir(dirname(htmlDest404Index), { recursive: true })
+            await fs.copyFile(htmlSrc, htmlDest404Index)
+          }
+          if (!options.buildExport) {
+            await fs.rm(htmlSrc)
+          }
         }
         // Skip 500.html in static export
         if (unnormalizedRoute === '/_global-error') {
diff --git a/test/e2e/app-dir/actions-unrecognized/actions-unrecognized.test.ts b/test/e2e/app-dir/actions-unrecognized/actions-unrecognized.test.ts
@@ -159,7 +159,8 @@ describe('unrecognized server actions', () => {
             // FIXME: Currently, an unrecognized id in an MPA action results in a 500.
             // This is not ideal, and ignores all nested `error.js` files, only showing the topmost one.
             expect(response.status()).toBe(500)
-            expect(response.headers()['content-type']).toStartWith('text/html')
+            expect(response.headers()['content-type']).toStartWith('text/plain')
+            expect(await response.text()).toBe('Internal Server Error')
             // In dev, the 500 page doesn't have any SSR'd html, so it won't show anything without JS.
             if (!isNextDev) {
               expect(await browser.elementByCss('body').text()).toContain(
