vercel · ztanner · Apr 29, 2024 · Apr 27, 2024
@@ -96,9 +96,10 @@ export function createMetadataComponents({
       resolve(undefined)
     } else {
       error = resolvedError
-      // If the error triggers in initial metadata resolving, re-resolve with proper error type.
-      // They'll be saved for flight data, when hydrates, it will replaces the SSR'd metadata with this.
-      // for not-found error: resolve not-found metadata
+      // If a not-found error is triggered during metadata resolution, we want to capture the metadata
+      // for the not-found route instead of whatever triggered the error. For all error types, we resolve an
+      // error, which will cause the outlet to throw it so it'll be handled by an error boundary
+      // (either an actual error, or an internal error that renders UI such as the NotFoundBoundary).
       if (!errorType && isNotFoundError(resolvedError)) {
         const [notFoundMetadataError, notFoundMetadata, notFoundViewport] =
           await resolveMetadata({

@@ -364,7 +364,8 @@ async function createComponentTreeInternal({
   const parallelRouteMap = await Promise.all(
     Object.keys(parallelRoutes).map(
       async (
-        parallelRouteKey
+        parallelRouteKey,
+        parallelRouteIndex
       ): Promise<[string, React.ReactNode, CacheNodeSeedData | null]> => {
         const isChildrenRouteKey = parallelRouteKey === 'children'
         const currentSegmentPath: FlightSegmentPath = firstItem
@@ -443,7 +444,11 @@ async function createComponentTreeInternal({
               injectedJS: injectedJSWithCurrentLayout,
               injectedFontPreloadTags: injectedFontPreloadTagsWithCurrentLayout,
               asNotFound,
-              metadataOutlet,
+              // The metadataOutlet is responsible for throwing any errors that were caught during metadata resolution.
+              // We only want to render an outlet once per segment, as otherwise the error will be triggered
+              // multiple times causing an uncaught error.
+              metadataOutlet:
+                parallelRouteIndex === 0 ? metadataOutlet : undefined,
               ctx,
               missingSlots,
             })

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>@bar slot</div>
+}
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>@bar slot</div>
+}
@@ -0,0 +1,9 @@
+import { notFound } from 'next/navigation'
+
+export function generateMetadata() {
+  notFound()
+}
+
+export default function Page() {
+  return <div>@bar slot</div>
+}
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>@foo slot</div>
+}
@@ -0,0 +1,9 @@
+export function generateMetadata() {
+  return {
+    title: 'Create Next App',
+  }
+}
+
+export default function Page() {
+  return <div>@foo slot</div>
+}
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>@foo slot</div>
+}
@@ -0,0 +1,9 @@
+import { notFound } from 'next/navigation'
+
+export function generateMetadata() {
+  notFound()
+}
+
+export default function Page() {
+  return <div>@foobar slot</div>
+}
@@ -0,0 +1,3 @@
+export default function Layout(props: { foobar: React.ReactNode }) {
+  return <>{props.foobar}</>
+}
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>Custom Not Found!</div>
+}
@@ -0,0 +1,9 @@
+import { notFound } from 'next/navigation'
+
+export function generateMetadata() {
+  notFound()
+}
+
+export default function Page() {
+  return <h1>Hello from Page</h1>
+}
@@ -0,0 +1,9 @@
+export function generateMetadata() {
+  return {
+    title: 'Create Next App',
+  }
+}
+
+export default function Page() {
+  return <h1>Hello from Page</h1>
+}
@@ -57,6 +57,36 @@ describe('parallel-route-not-found', () => {
     expect(warnings.length).toBe(0)
   })
 
+  it('should handle `notFound()` in generateMetadata on a page that also renders a parallel route', async () => {
+    const browser = await next.browser('/not-found-metadata/page-error')
+
+    // The page's `generateMetadata` function threw a `notFound()` error,
+    // so we should see the not found page.
+    expect(await browser.elementByCss('body').text()).toMatch(
+      /This page could not be found/
+    )
+  })
+
+  it('should handle `notFound()` in a slot', async () => {
+    const browser = await next.browser('/not-found-metadata/slot-error')
+
+    // The page's `generateMetadata` function threw a `notFound()` error,
+    // so we should see the not found page.
+    expect(await browser.elementByCss('body').text()).toMatch(
+      /This page could not be found/
+    )
+  })
+
+  it('should handle `notFound()` in a slot with no `children` slot', async () => {
+    const browser = await next.browser('/not-found-metadata/no-page')
+
+    // The page's `generateMetadata` function threw a `notFound()` error,
+    // so we should see the not found page.
+    expect(await browser.elementByCss('body').text()).toMatch(
+      /This page could not be found/
+    )
+  })
+
   if (isNextDev) {
     it('should not log any warnings for a regular not found page', async () => {
       const browser = await next.browser('/this-page-doesnt-exist')