next.js

1fe590fc - fix(server-hmr): metadata routes overwrite page runtime HMR handler (#92273)

fix(server-hmr): metadata routes overwrite page runtime HMR handler (#92273) ### What? Fix server HMR becoming unresponsive after a metadata route is loaded in the same Node.js process as an app page. ### Why? Turbopack loads separate runtime chunks for app pages and metadata routes (`robots.ts`, `sitemap.ts`, `manifest.ts`, `icon.tsx`, etc.) in the same Node.js process. Each runtime chunk embeds `dev-nodejs.ts` and produces a distinct `__turbopack_server_hmr_apply__` closure bound to its own `moduleFactories` and `devModuleCache`. Previously each runtime simply overwrote `globalThis.__turbopack_server_hmr_apply__`, so the last chunk to load silently won. Navigating to `/robots.txt` before an HMR update caused the metadata route runtime to overwrite the page runtime's handler. Subsequent HMR updates were dispatched only to the metadata route runtime, which has no knowledge of the page module — the page appeared frozen and stopped reflecting file changes. ### How? Replace the bare assignment with a multicast registry: 1. Each runtime appends its own `__turbopack_server_hmr_apply__` handler to `globalThis.__turbopack_server_hmr_handlers__[]`. 2. The first runtime to register installs a shared dispatcher as `globalThis.__turbopack_server_hmr_apply__` that iterates all registered handlers at call time (not install time), so newly loaded runtimes are always included. 3. On full cache reset, `hot-reloader-turbopack.ts` resets `__turbopack_server_hmr_handlers__` to `[]` so stale handlers from evicted chunks don't accumulate into the next generation. Because `dev-nodejs.ts` is embedded into the Turbopack binary via `include_dir!`, this fix requires rebuilding the native binary. ### Tests `test/development/app-dir/server-hmr/server-hmr.test.ts` — extended with `metadata route hmr` tests that load a metadata route before patching a page file, verifying HMR updates still reach the page runtime after a second runtime chunk is loaded. --------- Co-authored-by: Will Binns-Smith <wbinnssmith@users.noreply.github.com> Co-authored-by: Claude <noreply@anthropic.com>