[metadata] do not rethrow postpone when streaming metadata is not enabled

packages/next/src/lib/metadata/metadata.tsx

@@ -162,14 +162,14 @@ export function createMetadataComponents({
         } catch (notFoundMetadataErr) {
           // In PPR rendering we still need to throw the postpone error.
           // If metadata is postponed, React needs to be aware of the location of error.
-          if (isPostpone(notFoundMetadataErr)) {
+          if (serveStreamingMetadata && isPostpone(notFoundMetadataErr)) {
             throw notFoundMetadataErr
           }
         }
       }
       // In PPR rendering we still need to throw the postpone error.
       // If metadata is postponed, React needs to be aware of the location of error.
-      if (isPostpone(metadataErr)) {
+      if (serveStreamingMetadata && isPostpone(metadataErr)) {
         throw metadataErr
       }
       // We don't actually want to error in this component. We will

test/e2e/app-dir/metadata-static-generation/metadata-static-generation.test.ts

@@ -2,42 +2,46 @@ import { nextTestSetup } from 'e2e-utils'
 
 const isPPREnabled = process.env.__NEXT_EXPERIMENTAL_PPR === 'true'
 
-describe('app-dir - metadata-static-generation', () => {
-  const { next, isNextStart } = nextTestSetup({
-    files: __dirname,
-  })
+// PPR tests are covered in test/e2e/app-dir/ppr-metadata-blocking
+;(isPPREnabled ? describe.skip : describe)(
+  'app-dir - metadata-static-generation',
+  () => {
+    const { next, isNextStart } = nextTestSetup({
+      files: __dirname,
+    })
+
+    if (isNextStart) {
+      // Precondition for the following tests in build mode.
+      // This test is only useful for non-PPR mode as in PPR mode those routes
+      // are all listed in the prerender manifest.
+      it('should generate all pages static', async () => {
+        const prerenderManifest = JSON.parse(
+          await next.readFile('.next/prerender-manifest.json')
+        )
+        const staticRoutes = prerenderManifest.routes
+        expect(Object.keys(staticRoutes).sort()).toEqual([
+          '/',
+          '/suspenseful/static',
+        ])
+      })
+    }
 
-  if (isNextStart && !isPPREnabled) {
-    // Precondition for the following tests in build mode.
-    // This test is only useful for non-PPR mode as in PPR mode those routes
-    // are all listed in the prerender manifest.
-    it('should generate all pages static', async () => {
-      const prerenderManifest = JSON.parse(
-        await next.readFile('.next/prerender-manifest.json')
+    it('should contain async generated metadata in head for simple static page', async () => {
+      const $ = await next.render$('/')
+      expect($('head title').text()).toBe('index page')
+      expect($('head meta[name="description"]').attr('content')).toBe(
+        'index page description'
       )
-      const staticRoutes = prerenderManifest.routes
-      expect(Object.keys(staticRoutes).sort()).toEqual([
-        '/',
-        '/suspenseful/static',
-      ])
     })
-  }
-
-  it('should contain async generated metadata in head for simple static page', async () => {
-    const $ = await next.render$('/')
-    expect($('head title').text()).toBe('index page')
-    expect($('head meta[name="description"]').attr('content')).toBe(
-      'index page description'
-    )
-  })
 
-  it('should contain async generated metadata in head static page with suspenseful content', async () => {
-    const $ = await next.render$('/suspenseful/static')
-    expect($('head title').text()).toBe('suspenseful page - static')
-  })
+    it('should contain async generated metadata in head static page with suspenseful content', async () => {
+      const $ = await next.render$('/suspenseful/static')
+      expect($('head title').text()).toBe('suspenseful page - static')
+    })
 
-  it('should contain async generated metadata in head for dynamic page', async () => {
-    const $ = await next.render$('/suspenseful/dynamic')
-    expect($('head title').text()).toBe('suspenseful page - dynamic')
-  })
-})
+    it('should contain async generated metadata in head for dynamic page', async () => {
+      const $ = await next.render$('/suspenseful/dynamic')
+      expect($('head title').text()).toBe('suspenseful page - dynamic')
+    })
+  }
+)

test/e2e/app-dir/ppr-metadata-blocking/ppr-metadata-blocking-ppr-fallback.test.ts

@@ -0,0 +1,37 @@
+import { nextTestSetup } from 'e2e-utils'
+
+function countSubstring(str: string, substr: string): number {
+  return str.split(substr).length - 1
+}
+
+describe('ppr-metadata-blocking-ppr-fallback', () => {
+  const { next, skipped } = nextTestSetup({
+    files: __dirname,
+    skipDeployment: true,
+    env: {
+      __NEXT_EXPERIMENTAL_STATIC_SHELL_DEBUGGING: '1',
+    },
+  })
+
+  if (skipped) return
+
+  it('should not include metadata in partial shell when page is fully dynamic', async () => {
+    const $ = await next.render$('/fully-dynamic?__nextppronly=fallback')
+    expect(countSubstring($.html(), '<title>')).toBe(0)
+  })
+
+  it('should include viewport metadata in partial shell when metadata is dynamic under suspense', async () => {
+    const $ = await next.render$(
+      '/dynamic-metadata/partial?__nextppronly=fallback'
+    )
+    expect(countSubstring($.html(), '<title>')).toBe(0)
+    expect(countSubstring($.html(), '<meta name="viewport"')).toBe(1)
+  })
+
+  it('should include viewport metadata in partial shell when page is partially dynamic', async () => {
+    const $ = await next.render$('/dynamic-page/partial?__nextppronly=fallback')
+    expect($('head title').text()).toBe('dynamic-page - partial')
+    expect(countSubstring($.html(), '<title>')).toBe(1)
+    expect(countSubstring($.html(), '<meta name="viewport"')).toBe(1)
+  })
+})

test/e2e/app-dir/ppr-metadata-blocking/ppr-metadata-blocking.test.ts

@@ -7,7 +7,7 @@ function countSubstring(str: string, substr: string): number {
 }
 
 describe('ppr-metadata-blocking', () => {
-  const { next, isNextStart } = nextTestSetup({
+  const { next, isNextDev, isNextStart } = nextTestSetup({
     files: __dirname,
   })
 
@@ -55,8 +55,8 @@ describe('ppr-metadata-blocking', () => {
 
     it('should generate metadata in head when page content is static', async () => {
       const $ = await next.render$('/dynamic-metadata')
-      expect($('head title').text()).toBe('dynamic metadata')
       expect(countSubstring($.html(), '<title>')).toBe(1)
+      expect($('head title').text()).toBe('dynamic metadata')
 
       const browser = await next.browser('/dynamic-metadata')
       expect(await browser.waitForElementByCss('head title').text()).toBe(
@@ -69,8 +69,14 @@ describe('ppr-metadata-blocking', () => {
   describe('partial shell', () => {
     it('should insert metadata into head with dynamic metadata and wrapped under layout Suspense boundary', async () => {
       const $ = await next.render$('/dynamic-metadata/partial')
-      expect($('head title').text()).toBe('dynamic-metadata - partial')
-      expect(countSubstring($.html(), '<title>')).toBe(1)
+      // Dev: dynamic rendering
+      if (isNextDev) {
+        expect(countSubstring($.html(), '<title>')).toBe(1)
+        expect($('head title').text()).toBe('dynamic-metadata - partial')
+      } else {
+        // Production: PPR
+        expect(countSubstring($.html(), '<title>')).toBe(0)
+      }
 
       const browser = await next.browser('/dynamic-metadata/partial')
       expect(await browser.waitForElementByCss('head title').text()).toBe(
@@ -133,6 +139,9 @@ describe('ppr-metadata-blocking', () => {
 
         // Dynamic render should not have postponed header
         const headers = res1.headers
+        // In blocking mode of metadata, it's still postponed if metadata or page is dynamic.
+        // It won't behave differently when the bot is visiting.
+
         expect(headers.get('x-nextjs-postponed')).toBe(null)
 
         const $1 = cheerio.load(await res1.text())
@@ -142,7 +151,7 @@ describe('ppr-metadata-blocking', () => {
         const attribute2 = parseInt($2('[data-date]').attr('data-date'))
 
         // Two requests are dynamic and should not have the same data-date attribute
-        expect(attribute2).toBeGreaterThan(attribute1)
+        expect(attribute2).not.toEqual(attribute1)
         expect(attribute1).toBeTruthy()
       })
     })