This ensures when CSS requests stall that they are included in the route load timeout so that stalled CSS requests don't block us from falling back to a hard navigation. This handles a rare case noticed by @pacocoursey where a transition did not complete while attempting to load CSS assets.
## Bug
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
This adds support for returning an object from `rewrites` in `next.config.js` with `beforeFiles`, `afterFiles`, and `fallback` to allow specifying rewrites at different stages of routing. The existing support for returning an array for rewrites is still supported and behaves the same way. The documentation has been updated to include information on these new stages that can be rewritten and removes the outdated note of rewrites not being able to override pages.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [x] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
## Documentation / Examples
- [ ] Make sure the linting passes
In the current implementation, `idleTimeout` will always be thrown even if it didn't time out and `Promise.race` was resolved. This causes the error `Error: Route did not complete loading` on every route transition and Chrome Devtools will pause code execution if you have "Pause on exceptions" enabled.
This PR adds `resolvePromiseWithTimeout` which does the same thing as `Promise.race` and `idleTimeout`, but it cancels the rejection when it resolves successfully, in which case the error won't be thrown.
Fixes#21543.
This removes `import type` usage from our core files since `import type` requires a higher TypeScript version than currently expected.
Fixes: https://github.com/vercel/next.js/issues/19300
This pull request completely replaces our old page loader with a brand new route loader.
Our existing comprehensive test suite means I did not need to add a bunch of tests. I did add them where behavior was added or fixed.
Summary of the changes:
- Eagerly evaluates prefetched pages in browser idle time (speeds up transitions)
- Router is **no longer frozen** indefinitely if the Build Manifest never arrives
- Router is **no longer frozen** indefinitely if a page fails to bootstrap
- New `withFuture` utility instead of ad-hoc deduping per resource
- Prefetching is now delayed until browser idle time to not impact TTI
- Browsers without `prefetch` now fall back to eager evaluation instead of using `preload`
- We're now ready to serve non-static assets **with `no-store` without breaking prefetching**
- **Application can now hydrate without fetching CSS assets—this is a huge performance win that was previously blocking hydration**
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The minor size increase here is unfortunate, but we have to incur it for correctness.
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Fixes#18389Fixes#18642
