Pages router: Use attribute-based head children reconciler when strictNextHead is enabled
#65408
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
eps1lon
changed the title
strictNextHead is enabled
Tests Passed |
Stats from current PRDefault Build (Increase detected
|
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| buildDuration | 55.5s | 23.5s | N/A |
| buildDurationCached | 12.6s | 11.4s | N/A |
| nodeModulesSize | 360 MB | 360 MB | N/A |
| nextStartRea..uration (ms) | 724ms | 534ms | N/A |
Client Bundles (main, webpack)
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| 1103-HASH.js gzip | 31.9 kB | 31.9 kB | N/A |
| 1a9f679d-HASH.js gzip | 53.5 kB | 53.5 kB | N/A |
| 335-HASH.js gzip | 5.05 kB | 5.05 kB | ✓ |
| 7953.HASH.js gzip | 169 B | 169 B | ✓ |
| framework-HASH.js gzip | 45.2 kB | 45.2 kB | ✓ |
| main-app-HASH.js gzip | 231 B | 228 B | N/A |
| main-HASH.js gzip | 31.6 kB | 31.6 kB | N/A |
| webpack-HASH.js gzip | 1.65 kB | 1.65 kB | N/A |
| Overall change | 50.4 kB | 50.4 kB | ✓ |
Legacy Client Bundles (polyfills)
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| polyfills-HASH.js gzip | 31 kB | 31 kB | ✓ |
| Overall change | 31 kB | 31 kB | ✓ |
Client Pages
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| _app-HASH.js gzip | 192 B | 193 B | N/A |
| _error-HASH.js gzip | 192 B | 193 B | N/A |
| amp-HASH.js gzip | 507 B | 511 B | N/A |
| css-HASH.js gzip | 341 B | 343 B | N/A |
| dynamic-HASH.js gzip | 2.52 kB | 2.52 kB | ✓ |
| edge-ssr-HASH.js gzip | 266 B | 265 B | N/A |
| head-HASH.js gzip | 362 B | 365 B | N/A |
| hooks-HASH.js gzip | 392 B | 392 B | ✓ |
| image-HASH.js gzip | 4.27 kB | 4.27 kB | ✓ |
| index-HASH.js gzip | 268 B | 268 B | ✓ |
| link-HASH.js gzip | 2.69 kB | 2.7 kB | N/A |
| routerDirect..HASH.js gzip | 329 B | 328 B | N/A |
| script-HASH.js gzip | 397 B | 397 B | ✓ |
| withRouter-HASH.js gzip | 324 B | 324 B | ✓ |
| 1afbb74e6ecf..834.css gzip | 106 B | 106 B | ✓ |
| Overall change | 8.27 kB | 8.27 kB | ✓ |
Client Build Manifests
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| _buildManifest.js gzip | 483 B | 484 B | N/A |
| Overall change | 0 B | 0 B | ✓ |
Rendered Page Sizes
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| index.html gzip | 527 B | 527 B | ✓ |
| link.html gzip | 540 B | 539 B | N/A |
| withRouter.html gzip | 523 B | 523 B | ✓ |
| Overall change | 1.05 kB | 1.05 kB | ✓ |
Edge SSR bundle Size
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| edge-ssr.js gzip | 94.8 kB | 94.7 kB | N/A |
| page.js gzip | 182 kB | 182 kB | N/A |
| Overall change | 0 B | 0 B | ✓ |
Middleware size
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| middleware-b..fest.js gzip | 623 B | 624 B | N/A |
| middleware-r..fest.js gzip | 156 B | 156 B | ✓ |
| middleware.js gzip | 25.7 kB | 25.7 kB | N/A |
| edge-runtime..pack.js gzip | 839 B | 839 B | ✓ |
| Overall change | 995 B | 995 B | ✓ |
Next Runtimes
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| app-page-exp...dev.js gzip | 171 kB | 171 kB | ✓ |
| app-page-exp..prod.js gzip | 98.8 kB | 98.8 kB | ✓ |
| app-page-tur..prod.js gzip | 100 kB | 100 kB | ✓ |
| app-page-tur..prod.js gzip | 94.6 kB | 94.6 kB | ✓ |
| app-page.run...dev.js gzip | 157 kB | 157 kB | ✓ |
| app-page.run..prod.js gzip | 93.3 kB | 93.3 kB | ✓ |
| app-route-ex...dev.js gzip | 21.5 kB | 21.5 kB | ✓ |
| app-route-ex..prod.js gzip | 15.3 kB | 15.3 kB | ✓ |
| app-route-tu..prod.js gzip | 15.3 kB | 15.3 kB | ✓ |
| app-route-tu..prod.js gzip | 15 kB | 15 kB | ✓ |
| app-route.ru...dev.js gzip | 21.3 kB | 21.3 kB | ✓ |
| app-route.ru..prod.js gzip | 15 kB | 15 kB | ✓ |
| pages-api-tu..prod.js gzip | 9.55 kB | 9.55 kB | ✓ |
| pages-api.ru...dev.js gzip | 9.82 kB | 9.82 kB | ✓ |
| pages-api.ru..prod.js gzip | 9.55 kB | 9.55 kB | ✓ |
| pages-turbo...prod.js gzip | 21.5 kB | 21.5 kB | ✓ |
| pages.runtim...dev.js gzip | 22.1 kB | 22.1 kB | ✓ |
| pages.runtim..prod.js gzip | 21.5 kB | 21.5 kB | ✓ |
| server.runti..prod.js gzip | 51.7 kB | 51.7 kB | ✓ |
| Overall change | 964 kB | 964 kB | ✓ |
build cache Overall increase ⚠️
| vercel/next.js canary | vercel/next.js sebbie/pages-router-head-csr-reconciler | Change | |
|---|---|---|---|
| 0.pack gzip | 1.62 MB | 1.62 MB | N/A |
| index.pack gzip | 113 kB | 114 kB | |
| Overall change | 113 kB | 114 kB |
Diff details
Diff for edge-ssr.js
Diff too large to display
eps1lon
force-pushed
the
sebbie/pages-router-head-csr-reconciler
branch
3 times, most recently
from
6483771 to
f882a38
Compare
In React 19, tags within `<head>` may be reordered to improve performance e.g. the viewport is floated earlier into the head. This breaks the current mechanism of `<Head>` managing its children. Every child of `Head` used to be prefixed with another `<meta>` tag that indicated that the next sibling would be managed by Next.js. Since React now reorders tags, that sibling relationship is broken. Client-side reconciliation by the `head-manager` during navigation would be broken resulting in orphaned and dupliated `<meta>` tags. We no longer prefix `<Head>` managed tags with a `<meta>` tag and instead mark them as owned via `data-next-head`. The old algorithm was also O(n*m) and ignored reordering so we can do the same thing here.
eps1lon
force-pushed
the
sebbie/pages-router-head-csr-reconciler
branch
from
f882a38 to
e7ee686
Compare
eps1lon
requested review from
timneutkens,
ijjk,
shuding,
huozhi,
feedthejim,
ztanner and
wyattjoh
as code owners
eps1lon
changed the title
strictNextHead is enabledstrictNextHead is enabled
gnoff
approved these changes
May 6, 2024
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Required for #65058
In React 19, tags within
<head>may be reordered to improve performance e.g. the viewport is floated earlier into the head.This breaks the current mechanism of
<Head>managing its children.Every child of
Headused to be prefixed with another<meta>tag that indicated that the next sibling would be managed by Next.js.Since React now reorders tags, that sibling relationship is broken. Client-side reconciliation by the
head-managerduring navigation would be broken resulting in orphaned and dupliated<meta>tags.We no longer prefix
<Head>managed tags with a<meta>tag and instead mark them as owned viadata-next-head.The old algorithm was also O(n*m) and ignored reordering so we can do the same thing here.
Closes NEXT-3326