[PR #501] [MERGED] fix: use AsyncLocalStorage for per-request i18n locale state #623

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opened 2026-05-06 13:09:09 +02:00 by BreizhHardware · 0 comments

BreizhHardware commented

2026-05-06 13:09:09 +02:00

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📋 Pull Request Information

Original PR: https://github.com/cloudflare/vinext/pull/501
Author: @NathanDrake2406
Created: 3/12/2026
Status: ✅ Merged
Merged: 3/12/2026
Merged by: @james-elicx

Base: main ← Head: fix/i18n-locale-als

📝 Commits (1)

33969ed fix: use AsyncLocalStorage for per-request i18n locale state

📊 Changes

8 files changed (+944 additions, -660 deletions)

View changed files

📝 packages/vinext/src/entries/pages-server-entry.ts (+17 -11)
📝 packages/vinext/src/index.ts (+2 -0)
📝 packages/vinext/src/server/dev-server.ts (+656 -625)
➕ packages/vinext/src/shims/i18n-context.ts (+74 -0)
➕ packages/vinext/src/shims/i18n-state.ts (+65 -0)
📝 packages/vinext/src/shims/link.tsx (+4 -3)
📝 tests/__snapshots__/entry-templates.test.ts.snap (+17 -11)
📝 tests/link.test.ts (+109 -10)

📄 Description

Summary

Per-request i18n locale context (locale, defaultLocale, domainLocales, hostname) was stored on bare globalThis properties shared across concurrent requests
Under concurrent traffic (Cloudflare Workers or Node.js production), request A's locale could be overwritten by request B before A finishes rendering, causing <Link> components to produce incorrect locale-prefixed URLs
Introduces ALS-backed i18n state following the established router-state.ts / head-state.ts pattern:
- i18n-context.ts: bridge module with fallback globalThis accessors and a registration API (safe for both client and server import)
- i18n-state.ts: server-only module that registers ALS-backed accessors on import, providing per-request isolation
link.tsx now reads locale context via getI18nContext() instead of bare globalThis
Dev server uses ssrLoadModule("vinext/i18n-context") to set context on the SSR module instance (matching the existing setSSRContext pattern)
Production entry wraps rendering in runWithI18nState() and calls setI18nContext()

Test plan

Updated existing SSR locale domain test to use setI18nContext API
Added concurrent ALS isolation test: two simultaneous renders with different domain locale configs produce correct cross-domain hrefs independently
Added concurrent ALS isolation test: two simultaneous renders with different defaultLocale values produce correct locale prefixes (non-default gets prefix, default does not)
All 1015 tests pass across affected files (link.test.ts, features.test.ts, shims.test.ts, entry-templates.test.ts, safe-json.test.ts)
Typecheck and lint clean

_{🔄 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/501 **Author:** [@NathanDrake2406](https://github.com/NathanDrake2406) **Created:** 3/12/2026 **Status:** ✅ Merged **Merged:** 3/12/2026 **Merged by:** [@james-elicx](https://github.com/james-elicx) **Base:** `main` ← **Head:** `fix/i18n-locale-als` --- ### 📝 Commits (1) - [`33969ed`](https://github.com/cloudflare/vinext/commit/33969edeeeacdb295f37b21a6b7737cdd7d082c4) fix: use AsyncLocalStorage for per-request i18n locale state ### 📊 Changes **8 files changed** (+944 additions, -660 deletions) <details> <summary>View changed files</summary> 📝 `packages/vinext/src/entries/pages-server-entry.ts` (+17 -11) 📝 `packages/vinext/src/index.ts` (+2 -0) 📝 `packages/vinext/src/server/dev-server.ts` (+656 -625) ➕ `packages/vinext/src/shims/i18n-context.ts` (+74 -0) ➕ `packages/vinext/src/shims/i18n-state.ts` (+65 -0) 📝 `packages/vinext/src/shims/link.tsx` (+4 -3) 📝 `tests/__snapshots__/entry-templates.test.ts.snap` (+17 -11) 📝 `tests/link.test.ts` (+109 -10) </details> ### 📄 Description ## Summary - Per-request i18n locale context (`locale`, `defaultLocale`, `domainLocales`, `hostname`) was stored on bare `globalThis` properties shared across concurrent requests - Under concurrent traffic (Cloudflare Workers or Node.js production), request A's locale could be overwritten by request B before A finishes rendering, causing `<Link>` components to produce incorrect locale-prefixed URLs - Introduces ALS-backed i18n state following the established `router-state.ts` / `head-state.ts` pattern: - **`i18n-context.ts`**: bridge module with fallback `globalThis` accessors and a registration API (safe for both client and server import) - **`i18n-state.ts`**: server-only module that registers ALS-backed accessors on import, providing per-request isolation - `link.tsx` now reads locale context via `getI18nContext()` instead of bare `globalThis` - Dev server uses `ssrLoadModule("vinext/i18n-context")` to set context on the SSR module instance (matching the existing `setSSRContext` pattern) - Production entry wraps rendering in `runWithI18nState()` and calls `setI18nContext()` ## Test plan - [x] Updated existing SSR locale domain test to use `setI18nContext` API - [x] Added concurrent ALS isolation test: two simultaneous renders with different domain locale configs produce correct cross-domain hrefs independently - [x] Added concurrent ALS isolation test: two simultaneous renders with different `defaultLocale` values produce correct locale prefixes (non-default gets prefix, default does not) - [x] All 1015 tests pass across affected files (`link.test.ts`, `features.test.ts`, `shims.test.ts`, `entry-templates.test.ts`, `safe-json.test.ts`) - [x] Typecheck and lint clean --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>