[PR #372] [MERGED] perf: parallelise metadata and viewport resolution #519

New issue

Closed

opened 2026-05-06 13:08:31 +02:00 by BreizhHardware · 0 comments

BreizhHardware commented

2026-05-06 13:08:31 +02:00

Owner

📋 Pull Request Information

Original PR: https://github.com/cloudflare/vinext/pull/372
Author: @james-elicx
Created: 3/9/2026
Status: ✅ Merged
Merged: 3/9/2026
Merged by: @james-elicx

Base: main ← Head: j-branch-11

📝 Commits (6)

8812ae1 perf: parallelise metadata and viewport resolution
9077108 fix: propagate page generateMetadata errors to error boundary
2b3d082 Merge remote-tracking branch 'origin/main' into fix/metadata-error-propagation
71b5bfc test: update snapshots
622dd58 fix: log layout generateMetadata/generateViewport errors instead of silently swallowing them
4d126e6 regen snaps

📊 Changes

2 files changed (+196 additions, -189 deletions)

View changed files

📝 packages/vinext/src/server/app-dev-server.ts (+28 -27)
📝 tests/__snapshots__/entry-templates.test.ts.snap (+168 -162)

📄 Description

What

Converts sequential await loops for generateMetadata() and generateViewport() resolution into Promise.all, so all layouts' metadata is resolved concurrently rather than one-at-a-time.

Why

For deeply nested App Router layouts that do async I/O in generateMetadata() (KV reads, fetches, DB queries), the old serial approach meant total metadata resolution time was sum(individual times). With Promise.all it becomes max(individual times).

Details

Layout metadata errors are caught and logged (console.error) rather than crashing the page — a layout's generateMetadata() failing shouldn't take down the whole render
Page generateMetadata() errors are intentionally not swallowed — they propagate to the nearest error.tsx or global-error.tsx boundary, matching Next.js behavior
Snapshot updates reflect the parallelisation changes to the entry templates

#375 — pre-existing gap: generateMetadata() parent parameter is not yet supported

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/cloudflare/vinext/pull/372 **Author:** [@james-elicx](https://github.com/james-elicx) **Created:** 3/9/2026 **Status:** ✅ Merged **Merged:** 3/9/2026 **Merged by:** [@james-elicx](https://github.com/james-elicx) **Base:** `main` ← **Head:** `j-branch-11` --- ### 📝 Commits (6) - [`8812ae1`](https://github.com/cloudflare/vinext/commit/8812ae143c6ef4c104937f0d9d12d858ec6e8895) perf: parallelise metadata and viewport resolution - [`9077108`](https://github.com/cloudflare/vinext/commit/9077108b775d10f1e690b2bef77986d544102cda) fix: propagate page generateMetadata errors to error boundary - [`2b3d082`](https://github.com/cloudflare/vinext/commit/2b3d0823e017d2d3268afc269d703cbd302f93d1) Merge remote-tracking branch 'origin/main' into fix/metadata-error-propagation - [`71b5bfc`](https://github.com/cloudflare/vinext/commit/71b5bfc5b86f908eb0b3252f27b3d3b53a9b6999) test: update snapshots - [`622dd58`](https://github.com/cloudflare/vinext/commit/622dd585b8aa71411ec7bce4baf623568f183d17) fix: log layout generateMetadata/generateViewport errors instead of silently swallowing them - [`4d126e6`](https://github.com/cloudflare/vinext/commit/4d126e6ec7684ab9aaab4dbbb6560464a15d1ad3) regen snaps ### 📊 Changes **2 files changed** (+196 additions, -189 deletions) <details> <summary>View changed files</summary> 📝 `packages/vinext/src/server/app-dev-server.ts` (+28 -27) 📝 `tests/__snapshots__/entry-templates.test.ts.snap` (+168 -162) </details> ### 📄 Description ## What Converts sequential `await` loops for `generateMetadata()` and `generateViewport()` resolution into `Promise.all`, so all layouts' metadata is resolved concurrently rather than one-at-a-time. ## Why For deeply nested App Router layouts that do async I/O in `generateMetadata()` (KV reads, fetches, DB queries), the old serial approach meant total metadata resolution time was `sum(individual times)`. With `Promise.all` it becomes `max(individual times)`. ## Details - **Layout metadata errors** are caught and logged (`console.error`) rather than crashing the page — a layout's `generateMetadata()` failing shouldn't take down the whole render - **Page `generateMetadata()` errors** are intentionally not swallowed — they propagate to the nearest `error.tsx` or `global-error.tsx` boundary, matching Next.js behavior - Snapshot updates reflect the parallelisation changes to the entry templates ## Related - #375 — pre-existing gap: `generateMetadata()` `parent` parameter is not yet supported --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>