Implements `unstable_after`, which lets the user schedule work to be
executed after the response is finished.
### Implementation notes
- `unstable_after()` is a dynamic function (bypassable only with `export
dynamic = "force-static"`)
- Usable in: server components (including `generateMetadata`), actions,
route handlers, middleware
- It is meant to run its callbacks even if a response didn't complete
successfully (thrown error) or called `notFound()`/`redirect()`
- Currently gated behind a `experimental.after` feature flag, because it
touches many runtime bits (including a React monkeypatch...)
- The state for `unstable_after()` in a given request lives in
`requestAsyncStorage` (added via `RequestAsyncStorageWrapper`)
- the implementation is based around two functions that we inject via
`renderOpts`:
- `waitUntil(promise)` - keep a function invocation alive until a
promise settles. it is provided as a platform primitive in serverless
contexts, and a noop in `next start`
- for serverless (nodejs), Next.js will attempt to get `waitUntil` from
`globalThis[Symbol.for('@next/request-context')].get().waitUntil`. This
should be considered unstable for now. See
`packages/next/src/server/after/wait-until-builtin.ts` for details.
- `onClose(callback)` **[NEW]** - run something when a response is done.
basically `res.on('close', callback)`, but also implemented for Web APIs
- unfortunately, for Web, this requires some potentially expensive
tricks - see `packages/next/src/server/web/web-on-close.ts`
### What
This PR exposes new experimental configuration for next.js,
`experimental.reactCompiler`. Under the hood, this option configures to
use new experimental react compiler
(https://react.dev/learn/react-compiler#). `reactCompiler` value can be
either boolean or an object contains partial set of compiler itself's
configuration option.
For the webpack and turbopack both it is enabled by adding a babel
plugin for the react compiler. If user have an existing .babelrc, plugin
will be appended to the config. Otherwise, swc will still kicks in (for
webpack) or turbopack for the general transform but only compiler babel
plugin will run via babel.
---------
Co-authored-by: Tim Neutkens <tim@timneutkens.nl>
### What?
This PR adds an experimental option `clientTraceMetadata` that will use
the existing OpenTelemetry functionality to propagate conventional
OpenTelemetry trace information to the client.
The propagation metadata is propagated to the client via meta tags,
having a `name` and a `content` attribute containing the value of the
tracing value:
```html
<html>
<head>
<meta name="baggage" content="key1=val1,key2=val2">
<meta name="traceparent" content="00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01">
<meta name="custom" content="foobar">
</head>
</html>
```
The implementation adheres to OpenTelemetry as much as possible,
treating the meta tags as if they were tracing headers on outgoing
requests. The `clientTraceMetadata` will contain the keys of the
metadata that're going to injected for tracing purpose.
### Why?
Telemetry providers usually want to provide visibility across the entire
stack, meaning it is useful for users to be able to associate, for
example, web vitals on the client, with a span tree on the server. In
order to be able to correlate tracing events from the front- and
backend, it is necessary to share something like a trace ID or similar,
that the telemetry providers can pick up and stitch back together to
create a trace.
### How?
The tracer was extended with a method `getTracePropagationData()` that
returns the propagation data on the currently active OpenTelemetry
context.
We are using `makeGetServerInsertedHTML()` to inject the meta tags into
the HTML head for dynamic requests.
The meta tags are generated through using the newly added
`getTracePropagationData()` method on the tracer.
It is important to mention that **the trace information should only be
propagated for the initial loading of the page, including hard
navigations**. Any subsequent operations should not propagate trace data
from the server to the client, as the client generally is the root of
the trace. The exception is initial pageloads, since while the request
starts on the client, no JS has had the opportunity to run yet, meaning
there is no trace propagation on the client before the server hasn't
responded.
Situations that we do not want tracing information to be propagated from
the server to the client:
- _Prefetch requests._ Prefetches generally start on the client and are
already instrumented.
- _Any sort of static precomputation, including PPR._ If we include
trace information in static pages, it means that all clients that will
land on the static page will be part of the "precomputation" trace. This
would lead to gigantic traces with a ton of unrelated data that is not
useful. The special case is dev mode where it is likely fine to
propagate trace information, even for static content, since it is
usually not actually static in dev mode.
- _Clientside (soft) navigations._ Navigations start on the client and
are usually already instrumented.
### Alternatives considered
An implementation that purely lives in user-land could have been
implemented with `useServerInsertedHTML()`, however, that implementation
would be cumbersome for users to set up, since the implementation of
tracing would have to happen in a) the instrumentation hook, b) in a
client-component that is used in a top-level layout.
### Related issues/discussions
- https://github.com/vercel/next.js/issues/47660
- https://github.com/vercel/next.js/discussions/62353 (Could be used as
an alternative to the server-timing header)
- https://github.com/getsentry/sentry-javascript/issues/9571
---------
Co-authored-by: Jiachi Liu <inbox@huozhi.im>
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## For Maintainers
- Minimal description (aim for explaining to someone not on the team to
understand the PR)
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- Link both the Linear (Fixes NEXT-xxx) and the GitHub issues
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### What?
Adding support for supporting a custom fontFamily name when using
next/font
### Why?
By default, next/font hashes the font name when generating css to
achieve proper scoping.
However, that makes it impossible to use next/font with 3rd party
libraries that provide CSS with pre-defined font names.
### How?
To solve this, I've added a new argument to the next/font function call
– `usedFontFamilyName`.
It allows developers to pick the fontFamily name that is going to be
used in the CSS output instead of the default one and make it work with
vendor CSS files.
```
import { Inter } from "next/font/google";
const inter = Inter({
subsets: ["latin"],
fixedFontFamily: "Inter",
});
```
Fixes [#43452](https://github.com/vercel/next.js/discussions/43452)
---
Edit:
I've changed the implementation to use `disabledFontFamilyHashing`
boolean flag which removes the hashing but keeps the original font
family name instead of allowing a custom name
---------
Co-authored-by: JJ Kasper <jj@jjsweb.site>
Co-authored-by: Zack Tanner <1939140+ztanner@users.noreply.github.com>
### What
Remove `swcMinify` related branches as the option is deprecated and it's
always enabled
* Remove the related branches for checking `config.swcMinify`
* Remove the related telemetry about `swcMinify`
### What?
Do not reuse `Compiler` instance.
### Why?
It exists only to support preserving comments from `print()` API for
modules created with `parse()` API, but it causes a problem for
`transform()` for very huge apps.
### How?
- Closes https://github.com/swc-project/swc/issues/8932
- Fixes#48960
- Fixes#65436
### What
Reland #57448 , add react-server condition resolving and apply
server-only rules to middleware
Closes NEXT-1653
Closes NEXT-3333
### Why
Middleware as the pre-routing layer that is indended to be light-weight.
Since it's on edge runtime and only run on server but not on client, it
doesn't need to include the client react bundles. Hence we apply
`react-server` export condition, that if users import React we can only
bundle server required APIs and if users use React client hooks we can
error.
# What
Remove the previous deprecated flags and warnings
Removed deprecated types:
In `next.config.js`
- `experimental.incrementalCacheHandlerPath` (has moved to new options
in next 14)
- `experimental.isrMemoryCacheSize` (has moved to new options in next
14)
- `outputFileTracing` (not support customization anymore)
- `swcMinify` (not support customization anymore)
In `next/types`
- `unstable_includeFiles` (already deprecated for a while)
- `unstable_excludeFiles` (already deprecated for a while)
### What
Remove the auto appending `.xml` extension to the sitemap routes when
it's a dynamic route.
### Why
Previously we were adding `.xml` to `/[...paths/]sitemap` routes, but
the bad part is when you use it to generate multiple sitemaps with
`generateSitemaps` in format like `/[...paths/]sitemap.xml/[id]`, which
doesn't look good in url format and it can be inferred as xml with
content-type. Hence we don't need to add `.xml` in the url.
Before this change it could also result into the different url between
dev and prod:
dev: `/sitemap.xml/[id]`
prod: `/sitemap/[id].xml`
Now it's going to be aligned as `/sitemap/[id]`. Users can add extension
flexiblely.
Closes NEXT-3357
### What
* Extract `buildId` and server action encryption key into environment
variables for edge to make code more deterministic
* Fixed the legacy bad env names from #64108
* Always sort `routes` in prerender manifest for consistent output
* Change `environments` to `env` in middleware manifest, confirmed with
@javivelasco this is a fine change without need to bumping the version
### Why
Dynamic variants like `buildId`, SA `encryptionKey` and preview props
are different per build, which results to the non determinstic edge
bundles. Once we extracted them into env vars then the bundles become
deterministic which give us more space for optimization
Closes NEXT-3117
Reverts vercel/next.js#65425
Co-authored-by: Jiachi Liu <inbox@huozhi.im>
### What?
make sure children is first in loader tree to fix head css bug on client
navigation
### Why?
### How?
Fixes PACK-3028
---------
Co-authored-by: Tim Neutkens <tim@timneutkens.nl>
This PR promotes and renames experimental configuration options related
to server bundling:
- `serverComponentsExternalPackages` -> `serverExternalPackages`
- `bundlePagesExternals` -> `bundlePagesRouterDependencies`
Existing docs for `serverComponentsExternalPackages` was changed.
New docs for `bundlePagesRouterDependencies` were added.
Closes NEXT-3332
