[Fizz] implement onHeaders and headersLengthHint options
#27641
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
facebook-github-bot
added
CLA Signed
React Core Team
gnoff
force-pushed
the
fizz-on-headers
branch
from
c8dcce2 to
18c3ec1
Compare
sebmarkbage
reviewed
Nov 7, 2023
| @@ -60,6 +63,8 @@ type Options = { | |||
| unstable_externalRuntimeSrc?: string | BootstrapScriptDescriptor, | |||
| importMap?: ImportMap, | |||
| formState?: ReactFormState<any, any> | null, | |||
| onHeaders?: (headers: HeadersDescriptor) => void, | |||
| headersLengthHint?: number, | |||
There was a problem hiding this comment.
Hints seems pretty vague. Can't I specify a max? maxHeadersLength?
There was a problem hiding this comment.
It's not a max because I don't want to compute the next headers length before deciding if it is going to be a header. I chose hint b/c I want it to communicate that this number is a target not a hard limit. You'll get a header object "near" this length. Also it's already a little imprecise b/c it's code unit length which can be 1x to 4x in byte length when sent via utf8. My guess is the average english website will have a byte length around close to 1x the headers length but in other character sets the headers are going to be longer
There was a problem hiding this comment.
I don't think HTTP headers really support utf8 in practice. Traditionally it was ISO-8859-1 but in practice only the ASCII subset should be used. So either we assume that the URLs have already been encoded or we should arguably encode the URLs ourselves otherwise.
sebmarkbage
reviewed
Nov 7, 2023
| request.completedRootSegment === null | ||
| ? request.pendingRootTasks === 0 | ||
| : request.completedRootSegment.status !== POSTPONED; | ||
| emitEarlyPreloads(request.renderState, request.resumableState, shellComplete); |
There was a problem hiding this comment.
This can potentially happen a lot when you drain a queue often. Unfortunate to add all these extra checks here.
Additionally, if this is happening in a drain event, you might be in a bad context to do something about it. Other other callback tend to be top of stack like scheduled work.
This is also impossible in all APIs but Node.
I wonder if we should just move this into its own function for Node or something.
sebmarkbage
reviewed
Nov 7, 2023
| // I extracted this function out because we want to ensure we consistently emit preloads before | ||
| // transitioning to the next request stage and this transition can happen in multiple places in this | ||
| // implementation. | ||
| function completeWork(request: Request) { |
There was a problem hiding this comment.
It's a little confusing that this name doesn't have anything to do with the same function name in Fiber.
There was a problem hiding this comment.
completeAll is analagous to onAllReady. similar to completeShell for onShellReady
sebmarkbage
reviewed
Nov 7, 2023
| referrerPolicy: props.refererPolicy, | ||
| }); | ||
| headers.highImagePreloads += header; | ||
| headers.remainingCapacity -= header.length; |
There was a problem hiding this comment.
If this ends up exceeding capacity, can't we just throw it away and and take the other path instead?
So we don't need the hacky "hint" which may or may not be fully honored.
There was a problem hiding this comment.
yeah, i suppose you only pay the cost once so we can do the limit thing. But per my other comment the limit is still quite imprecise
sebmarkbage
reviewed
Nov 7, 2023
| @@ -101,6 +103,12 @@ export function prepareHostDispatcher() { | |||
| ReactDOMCurrentDispatcher.current = ReactDOMServerDispatcher; | |||
| } | |||
|
|
|||
| export type HeadersDescriptor = { | |||
| Link: string, | |||
There was a problem hiding this comment.
Maybe this field should be optional just to indicate that in the future we might not include it in every call. Given that this type will be reflected in public types.
sebmarkbage
reviewed
Nov 7, 2023
| // This escaping function is only safe to use for href values being written into | ||
| // a "Link" header in between `<` and `>` characters. The primary concern with the href is | ||
| // to escape the bounding characters as well as new lines. This is unsafe to use in any other | ||
| // context |
There was a problem hiding this comment.
Is tabs a concern here?
There was a problem hiding this comment.
From my research no, it is specifically \r\n. However this is what the spec says, it's possible there are clients in the wild that are more permissive in what breaks out of the href parsing context
sebmarkbage
reviewed
Nov 7, 2023
| // This is hacky but we always append headers into each queue assuming it is a subsequent | ||
| // header. This means that if the string has any length at all it will start with ", " | ||
| // so we truncate it here. This is ugly but the alternatives are to use arrays and join | ||
| // or to length check the queue each time we write to it. This is the most efficient option |
There was a problem hiding this comment.
Well, this will always flatten the ropes and clone it I think so might not be so good. We should just check each time before we add. Since it's interned if (linkHeader !== '') linkHeader += ', '; might be fastest.
gnoff
force-pushed
the
fizz-on-headers
branch
from
18c3ec1 to
4c3bcb6
Compare
gnoff
force-pushed
the
fizz-on-headers
branch
from
4c3bcb6 to
f4899fd
Compare
sebmarkbage
approved these changes
Nov 7, 2023
gnoff
force-pushed
the
fizz-on-headers
branch
2 times, most recently
from
74128be to
6523996
Compare
During a render it can be useful to emit headers to start the process of preloading without waiting for the shell to complete. If provided an `onHeadersReady` callback option Fizz will call this callback with some headers. Currently this is implemented as a set of preload link headers that are generated during the first performWork pass. After this pass preloads are handled as they were preious to this change and emitted as tags. Since headers are not streamed typically we are choosing an API that provides headers once. Because of this we need to choose a point at which to provide headers once even if we could in theory wait longer to accumulate more. It is possible that a better API is to allow the caller to tell Fizz when it wants whatever headers have accumulated however in practice this would require having some secondary header outside of react that is blocking sending headers and that is considered not a likely ocurrence In this commit we add the option to pass `onHeadersReady` to static and dynamic render entrypoints. This is not yet wired up to anything so it will never be called. This will be added in a subsequent commit.
gnoff
force-pushed
the
fizz-on-headers
branch
from
6523996 to
4140b11
Compare
github-actions bot
pushed a commit
that referenced
this pull request
Nov 7, 2023
Adds a new option to `react-dom/server` entrypoints.
`onHeaders: (headers: Headers) => void` (non node envs)
`onHeaders: (headers: { Link?: string }) => void` (node envs)
When any `renderTo...` or `prerender...` function is called and this
option is provided the supplied function will be called sometime on or
before completion of the render with some preload link headers.
When provided during a `renderTo...` the callback will usually be called
after the first pass at work. The idea here is we want to get a set of
headers to start the browser loading well before the shell is ready. We
don't wait for the shell because if we did we may as well send the
preloads as tags in the HTML.
When provided during a `prerender...` the callback will be called after
the entire prerender is complete. The idea here is we are not responding
to a live request and it is preferable to capture as much as possible
for preloading as Headers in case the prerender was unable to finish the
shell.
Currently the following resources are always preloaded as headers when
the option is provided
1. prefetchDNS and preconnects
2. font preloads
3. high priority image preloads
Additionally if we are providing headers when the shell is incomplete
(regardless of whether it is render or prerender) we will also include
any stylesheet Resources (ones with a precedence prop)
There is a second option `maxHeadersLength?: number` which allows you to
specify the maximum length of the header content in unicode code units.
This is what you get when you read the length property of a string in
javascript. It's improtant to note that this is not the same as the
utf-8 byte length when these headers are serialized in a Response. The
utf8 representation may be the same size, or larger but it will never be
smaller.
If you do not supply a `maxHeadersLength` we defaul to `2000`. This was
chosen as half the value of the max headers length supported by commonly
known web servers and CDNs. many browser and web server can support
significantly more headers than this so you can use this option to
increase the headers limit. You can also of course use it to be even
more conservative. Again it is important to keep in mind there is no
direct translation between the max length and the bytelength and so if
you want to stay under a certain byte length you need to be potentially
more aggressive in the maxHeadersLength you choose.
Conceptually `onHeaders` could be called more than once as new headers
are discovered however if we haven't started flushing yet but since most
APIs for the server including the web standard Response only allow you
to set headers once the current implementation will only call it one
time
DiffTrain build for [2983249](2983249)
gnoff
added a commit
to gnoff/next.js
that referenced
this pull request
Nov 7, 2023
- facebook/react#27641 - facebook/react#27661 - facebook/react#27640 - facebook/react#27595 - facebook/react#27600 - facebook/react#27598 - facebook/react#27590 - facebook/react#27606 - facebook/react#27608 - facebook/react#27601 - facebook/react#27616 - facebook/react#27615 - facebook/react#27614 - facebook/react#27599 - facebook/react#27597 - facebook/react#27525 - facebook/react#27571
kodiakhq bot
pushed a commit
to vercel/next.js
that referenced
this pull request
Nov 7, 2023
Updates React from 08a39539f to 2983249dd. ### React upstream changes - facebook/react#27641 - facebook/react#27661 - facebook/react#27640 - facebook/react#27595 - facebook/react#27600 - facebook/react#27598 - facebook/react#27590 - facebook/react#27606 - facebook/react#27608 - facebook/react#27601 - facebook/react#27616 - facebook/react#27615 - facebook/react#27614 - facebook/react#27599 - facebook/react#27597 - facebook/react#27525 - facebook/react#27571 Updates @types/react to 18.2.37 Updates @types/react-dom to 18.2.15
EdisonVan
pushed a commit
to EdisonVan/react
that referenced
this pull request
Apr 15, 2024
…k#27641) Adds a new option to `react-dom/server` entrypoints. `onHeaders: (headers: Headers) => void` (non node envs) `onHeaders: (headers: { Link?: string }) => void` (node envs) When any `renderTo...` or `prerender...` function is called and this option is provided the supplied function will be called sometime on or before completion of the render with some preload link headers. When provided during a `renderTo...` the callback will usually be called after the first pass at work. The idea here is we want to get a set of headers to start the browser loading well before the shell is ready. We don't wait for the shell because if we did we may as well send the preloads as tags in the HTML. When provided during a `prerender...` the callback will be called after the entire prerender is complete. The idea here is we are not responding to a live request and it is preferable to capture as much as possible for preloading as Headers in case the prerender was unable to finish the shell. Currently the following resources are always preloaded as headers when the option is provided 1. prefetchDNS and preconnects 2. font preloads 3. high priority image preloads Additionally if we are providing headers when the shell is incomplete (regardless of whether it is render or prerender) we will also include any stylesheet Resources (ones with a precedence prop) There is a second option `maxHeadersLength?: number` which allows you to specify the maximum length of the header content in unicode code units. This is what you get when you read the length property of a string in javascript. It's improtant to note that this is not the same as the utf-8 byte length when these headers are serialized in a Response. The utf8 representation may be the same size, or larger but it will never be smaller. If you do not supply a `maxHeadersLength` we defaul to `2000`. This was chosen as half the value of the max headers length supported by commonly known web servers and CDNs. many browser and web server can support significantly more headers than this so you can use this option to increase the headers limit. You can also of course use it to be even more conservative. Again it is important to keep in mind there is no direct translation between the max length and the bytelength and so if you want to stay under a certain byte length you need to be potentially more aggressive in the maxHeadersLength you choose. Conceptually `onHeaders` could be called more than once as new headers are discovered however if we haven't started flushing yet but since most APIs for the server including the web standard Response only allow you to set headers once the current implementation will only call it one time
bigfootjon
pushed a commit
that referenced
this pull request
Apr 18, 2024
Adds a new option to `react-dom/server` entrypoints.
`onHeaders: (headers: Headers) => void` (non node envs)
`onHeaders: (headers: { Link?: string }) => void` (node envs)
When any `renderTo...` or `prerender...` function is called and this
option is provided the supplied function will be called sometime on or
before completion of the render with some preload link headers.
When provided during a `renderTo...` the callback will usually be called
after the first pass at work. The idea here is we want to get a set of
headers to start the browser loading well before the shell is ready. We
don't wait for the shell because if we did we may as well send the
preloads as tags in the HTML.
When provided during a `prerender...` the callback will be called after
the entire prerender is complete. The idea here is we are not responding
to a live request and it is preferable to capture as much as possible
for preloading as Headers in case the prerender was unable to finish the
shell.
Currently the following resources are always preloaded as headers when
the option is provided
1. prefetchDNS and preconnects
2. font preloads
3. high priority image preloads
Additionally if we are providing headers when the shell is incomplete
(regardless of whether it is render or prerender) we will also include
any stylesheet Resources (ones with a precedence prop)
There is a second option `maxHeadersLength?: number` which allows you to
specify the maximum length of the header content in unicode code units.
This is what you get when you read the length property of a string in
javascript. It's improtant to note that this is not the same as the
utf-8 byte length when these headers are serialized in a Response. The
utf8 representation may be the same size, or larger but it will never be
smaller.
If you do not supply a `maxHeadersLength` we defaul to `2000`. This was
chosen as half the value of the max headers length supported by commonly
known web servers and CDNs. many browser and web server can support
significantly more headers than this so you can use this option to
increase the headers limit. You can also of course use it to be even
more conservative. Again it is important to keep in mind there is no
direct translation between the max length and the bytelength and so if
you want to stay under a certain byte length you need to be potentially
more aggressive in the maxHeadersLength you choose.
Conceptually `onHeaders` could be called more than once as new headers
are discovered however if we haven't started flushing yet but since most
APIs for the server including the web standard Response only allow you
to set headers once the current implementation will only call it one
time
DiffTrain build for commit 2983249.
alexandresoro
pushed a commit
to alexandresoro/ouca-web
that referenced
this pull request
Jan 17, 2025
This PR contains the following updates:
| Package | Type | Update | Change |
|---|---|---|---|
| [@types/react](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/react) ([source](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/react)) | devDependencies | major | [`18.3.18` -> `19.0.7`](https://renovatebot.com/diffs/npm/@types%2freact/18.3.18/19.0.7) |
| [@types/react-dom](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/react-dom) ([source](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/react-dom)) | devDependencies | major | [`18.3.5` -> `19.0.3`](https://renovatebot.com/diffs/npm/@types%2freact-dom/18.3.5/19.0.3) |
| [react](https://react.dev/) ([source](https://github.com/facebook/react/tree/HEAD/packages/react)) | dependencies | major | [`18.3.1` -> `19.0.0`](https://renovatebot.com/diffs/npm/react/18.3.1/19.0.0) |
| [react-dom](https://react.dev/) ([source](https://github.com/facebook/react/tree/HEAD/packages/react-dom)) | dependencies | major | [`18.3.1` -> `19.0.0`](https://renovatebot.com/diffs/npm/react-dom/18.3.1/19.0.0) |
---
### Release Notes
<details>
<summary>facebook/react (react)</summary>
### [`v19.0.0`](https://github.com/facebook/react/blob/HEAD/CHANGELOG.md#1900-December-5-2024)
[Compare Source](https://github.com/facebook/react/compare/v18.3.1...v19.0.0)
Below is a list of all new features, APIs, deprecations, and breaking changes. Read [React 19 release post](https://react.dev/blog/2024/04/25/react-19) and [React 19 upgrade guide](https://react.dev/blog/2024/04/25/react-19-upgrade-guide) for more information.
> Note: To help make the upgrade to React 19 easier, we’ve published a react@18.3 release that is identical to 18.2 but adds warnings for deprecated APIs and other changes that are needed for React 19. We recommend upgrading to React 18.3.1 first to help identify any issues before upgrading to React 19.
##### New Features
##### React
- Actions: `startTransition` can now accept async functions. Functions passed to `startTransition` are called “Actions”. A given Transition can include one or more Actions which update state in the background and update the UI with one commit. In addition to updating state, Actions can now perform side effects including async requests, and the Action will wait for the work to finish before finishing the Transition. This feature allows Transitions to include side effects like `fetch()` in the pending state, and provides support for error handling, and optimistic updates.
- `useActionState`: is a new hook to order Actions inside of a Transition with access to the state of the action, and the pending state. It accepts a reducer that can call Actions, and the initial state used for first render. It also accepts an optional string that is used if the action is passed to a form `action` prop to support progressive enhancement in forms.
- `useOptimistic`: is a new hook to update state while a Transition is in progress. It returns the state, and a set function that can be called inside a transition to “optimistically” update the state to expected final value immediately while the Transition completes in the background. When the transition finishes, the state is updated to the new value.
- `use`: is a new API that allows reading resources in render. In React 19, `use` accepts a promise or Context. If provided a promise, `use` will suspend until a value is resolved. `use` can only be used in render but can be called conditionally.
- `ref` as a prop: Refs can now be used as props, removing the need for `forwardRef`.
- **Suspense sibling pre-warming**: When a component suspends, React will immediately commit the fallback of the nearest Suspense boundary, without waiting for the entire sibling tree to render. After the fallback commits, React will schedule another render for the suspended siblings to “pre-warm” lazy requests.
##### React DOM Client
- `<form> action` prop: Form Actions allow you to manage forms automatically and integrate with `useFormStatus`. When a `<form> action` succeeds, React will automatically reset the form for uncontrolled components. The form can be reset manually with the new `requestFormReset` API.
- `<button> and <input> formAction` prop: Actions can be passed to the `formAction` prop to configure form submission behavior. This allows using different Actions depending on the input.
- `useFormStatus`: is a new hook that provides the status of the parent `<form> action`, as if the form was a Context provider. The hook returns the values: `pending`, `data`, `method`, and `action`.
- Support for Document Metadata: We’ve added support for rendering document metadata tags in components natively. React will automatically hoist them into the `<head>` section of the document.
- Support for Stylesheets: React 19 will ensure stylesheets are inserted into the `<head>` on the client before revealing the content of a Suspense boundary that depends on that stylesheet.
- Support for async scripts: Async scripts can be rendered anywhere in the component tree and React will handle ordering and deduplication.
- Support for preloading resources: React 19 ships with `preinit`, `preload`, `prefetchDNS`, and `preconnect` APIs to optimize initial page loads by moving discovery of additional resources like fonts out of stylesheet loading. They can also be used to prefetch resources used by an anticipated navigation.
##### React DOM Server
- Added `prerender` and `prerenderToNodeStream` APIs for static site generation. They are designed to work with streaming environments like Node.js Streams and Web Streams. Unlike `renderToString`, they wait for data to load for HTML generation.
##### React Server Components
- RSC features such as directives, server components, and server functions are now stable. This means libraries that ship with Server Components can now target React 19 as a peer dependency with a react-server export condition for use in frameworks that support the Full-stack React Architecture. The underlying APIs used to implement a React Server Components bundler or framework do not follow semver and may break between minors in React 19.x. See [docs](https://19.react.dev/reference/rsc/server-components) for how to support React Server Components.
##### Deprecations
- Deprecated: `element.ref` access: React 19 supports ref as a prop, so we’re deprecating `element.ref` in favor of `element.props.ref`. Accessing will result in a warning.
- `react-test-renderer`: In React 19, react-test-renderer logs a deprecation warning and has switched to concurrent rendering for web usage. We recommend migrating your tests to [@​testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@​testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro)
##### Breaking Changes
React 19 brings in a number of breaking changes, including the removals of long-deprecated APIs. We recommend first upgrading to `18.3.1`, where we've added additional deprecation warnings. Check out the [upgrade guide](https://19.react.dev/blog/2024/04/25/react-19-upgrade-guide) for more details and guidance on codemodding.
##### React
- New JSX Transform is now required: We introduced [a new JSX transform](https://legacy.reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html) in 2020 to improve bundle size and use JSX without importing React. In React 19, we’re adding additional improvements like using ref as a prop and JSX speed improvements that require the new transform.
- Errors in render are not re-thrown: Errors that are not caught by an Error Boundary are now reported to window.reportError. Errors that are caught by an Error Boundary are reported to console.error. We’ve introduced `onUncaughtError` and `onCaughtError` methods to `createRoot` and `hydrateRoot` to customize this error handling.
- Removed: `propTypes`: Using `propTypes` will now be silently ignored. If required, we recommend migrating to TypeScript or another type-checking solution.
- Removed: `defaultProps` for functions: ES6 default parameters can be used in place. Class components continue to support `defaultProps` since there is no ES6 alternative.
- Removed: `contextTypes` and `getChildContext`: Legacy Context for class components has been removed in favor of the `contextType` API.
- Removed: string refs: Any usage of string refs need to be migrated to ref callbacks.
- Removed: Module pattern factories: A rarely used pattern that can be migrated to regular functions.
- Removed: `React.createFactory`: Now that JSX is broadly supported, all `createFactory` usage can be migrated to JSX components.
- Removed: `react-test-renderer/shallow`: This has been a re-export of [react-shallow-renderer](https://github.com/enzymejs/react-shallow-renderer) since React 18. If needed, you can continue to use the third-party package directly. We recommend using [@​testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@​testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro) instead.
##### React DOM
- Removed: `react-dom/test-utils`: We’ve moved `act` from `react-dom/test-utils` to react. All other utilities have been removed.
- Removed: `ReactDOM`.`render`, `ReactDOM`.`hydrate`: These have been removed in favor of the concurrent equivalents: `ReactDOM`.`createRoot` and `ReactDOM.hydrateRoot`.
- Removed: `unmountComponentAtNode`: Removed in favor of `root.unmount()`.
- Removed: `ReactDOM`.`findDOMNode`: You can replace `ReactDOM`.`findDOMNode` with DOM Refs.
##### Notable Changes
##### React
- `<Context>` as a provider: You can now render `<Context>` as a provider instead of `<Context.Provider>`.
- Cleanup functions for refs: When the component unmounts, React will call the cleanup function returned from the ref callback.
- `useDeferredValue` initial value argument: When provided, `useDeferredValue` will return the initial value for the initial render of a component, then schedule a re-render in the background with the `deferredValue` returned.
- Support for Custom Elements: React 19 now passes all tests on [Custom Elements Everywhere](https://custom-elements-everywhere.com/).
- StrictMode changes: `useMemo` and `useCallback` will now reuse the memoized results from the first render, during the second render. Additionally, StrictMode will now double-invoke ref callback functions on initial mount.
- UMD builds removed: To load React 19 with a script tag, we recommend using an ESM-based CDN such as [esm.sh](http://esm.sh).
##### React DOM
- Diffs for hydration errors: In the case of a mismatch, React 19 logs a single error with a diff of the mismatched content.
- Compatibility with third-party scripts and extensions: React will now force a client re-render to fix up any mismatched content caused by elements inserted by third-party JS.
##### TypeScript Changes
The most common changes can be codemodded with `npx types-react-codemod@latest preset-19 ./path-to-your-react-ts-files`.
- Removed deprecated TypeScript types:
- `ReactChild` (replacement: `React.ReactElement | number | string)`
- `ReactFragment` (replacement: `Iterable<React.ReactNode>`)
- `ReactNodeArray` (replacement: `ReadonlyArray<React.ReactNode>`)
- `ReactText` (replacement: `number | string`)
- `VoidFunctionComponent` (replacement: `FunctionComponent`)
- `VFC` (replacement: `FC`)
- Moved to `prop-types`: `Requireable`, `ValidationMap`, `Validator`, `WeakValidationMap`
- Moved to `create-react-class`: `ClassicComponentClass`, `ClassicComponent`, `ClassicElement`, `ComponentSpec`, `Mixin`, `ReactChildren`, `ReactHTML`, `ReactSVG`, `SFCFactory`
- Disallow implicit return in refs: refs can now accept cleanup functions. When you return something else, we can’t tell if you intentionally returned something not meant to clean up or returned the wrong value. Implicit returns of anything but functions will now error.
- Require initial argument to `useRef`: The initial argument is now required to match `useState`, `createContext` etc
- Refs are mutable by default: Ref objects returned from `useRef()` are now always mutable instead of sometimes being immutable. This feature was too confusing for users and conflicted with legit cases where refs were managed by React and manually written to.
- Strict `ReactElement` typing: The props of React elements now default to `unknown` instead of `any` if the element is typed as `ReactElement`
- JSX namespace in TypeScript: The global `JSX` namespace is removed to improve interoperability with other libraries using JSX. Instead, the JSX namespace is available from the React package: `import { JSX } from 'react'`
- Better `useReducer` typings: Most `useReducer` usage should not require explicit type arguments.\
For example,
```diff
-useReducer<React.Reducer<State, Action>>(reducer)
+useReducer(reducer)
```
or
```diff
-useReducer<React.Reducer<State, Action>>(reducer)
+useReducer<State, Action>(reducer)
```
##### All Changes
##### React
- Add support for async Actions ([#​26621](https://github.com/facebook/react/pull/26621), [#​26726](https://github.com/facebook/react/pull/26726), [#​28078](https://github.com/facebook/react/pull/28078), [#​28097](https://github.com/facebook/react/pull/28097), [#​29226](https://github.com/facebook/react/pull/29226), [#​29618](https://github.com/facebook/react/pull/29618), [#​29670](https://github.com/facebook/react/pull/29670), [#​26716](https://github.com/facebook/react/pull/26716) by [@​acdlite](https://github.com/acdlite) and [@​sebmarkbage](https://github.com/sebmarkbage))
- Add `useActionState()` hook to update state based on the result of a Form Action ([#​27270](https://github.com/facebook/react/pull/27270), [#​27278](https://github.com/facebook/react/pull/27278), [#​27309](https://github.com/facebook/react/pull/27309), [#​27302](https://github.com/facebook/react/pull/27302), [#​27307](https://github.com/facebook/react/pull/27307), [#​27366](https://github.com/facebook/react/pull/27366), [#​27370](https://github.com/facebook/react/pull/27370), [#​27321](https://github.com/facebook/react/pull/27321), [#​27374](https://github.com/facebook/react/pull/27374), [#​27372](https://github.com/facebook/react/pull/27372), [#​27397](https://github.com/facebook/react/pull/27397), [#​27399](https://github.com/facebook/react/pull/27399), [#​27460](https://github.com/facebook/react/pull/27460), [#​28557](https://github.com/facebook/react/pull/28557), [#​27570](https://github.com/facebook/react/pull/27570), [#​27571](https://github.com/facebook/react/pull/27571), [#​28631](https://github.com/facebook/react/pull/28631), [#​28788](https://github.com/facebook/react/pull/28788), [#​29694](https://github.com/facebook/react/pull/29694), [#​29695](https://github.com/facebook/react/pull/29695), [#​29694](https://github.com/facebook/react/pull/29694), [#​29665](https://github.com/facebook/react/pull/29665), [#​28232](https://github.com/facebook/react/pull/28232), [#​28319](https://github.com/facebook/react/pull/28319) by [@​acdlite](https://github.com/acdlite), [@​eps1lon](https://github.com/eps1lon), and [@​rickhanlonii](https://github.com/rickhanlonii))
- Add `use()` API to read resources in render ([#​25084](https://github.com/facebook/react/pull/25084), [#​25202](https://github.com/facebook/react/pull/25202), [#​25207](https://github.com/facebook/react/pull/25207), [#​25214](https://github.com/facebook/react/pull/25214), [#​25226](https://github.com/facebook/react/pull/25226), [#​25247](https://github.com/facebook/react/pull/25247), [#​25539](https://github.com/facebook/react/pull/25539), [#​25538](https://github.com/facebook/react/pull/25538), [#​25537](https://github.com/facebook/react/pull/25537), [#​25543](https://github.com/facebook/react/pull/25543), [#​25561](https://github.com/facebook/react/pull/25561), [#​25620](https://github.com/facebook/react/pull/25620), [#​25615](https://github.com/facebook/react/pull/25615), [#​25922](https://github.com/facebook/react/pull/25922), [#​25641](https://github.com/facebook/react/pull/25641), [#​25634](https://github.com/facebook/react/pull/25634), [#​26232](https://github.com/facebook/react/pull/26232), [#​26536](https://github.com/facebook/react/pull/26535), [#​26739](https://github.com/facebook/react/pull/26739), [#​28233](https://github.com/facebook/react/pull/28233) by [@​acdlite](https://github.com/acdlite), [@​MofeiZ](https://github.com/mofeiZ), [@​sebmarkbage](https://github.com/sebmarkbage), [@​sophiebits](https://github.com/sophiebits), [@​eps1lon](https://github.com/eps1lon), and [@​hansottowirtz](https://github.com/hansottowirtz))
- Add `useOptimistic()` hook to display mutated state optimistically during an async mutation ([#​26740](https://github.com/facebook/react/pull/26740), [#​26772](https://github.com/facebook/react/pull/26772), [#​27277](https://github.com/facebook/react/pull/27277), [#​27453](https://github.com/facebook/react/pull/27453), [#​27454](https://github.com/facebook/react/pull/27454), [#​27936](https://github.com/facebook/react/pull/27936) by [@​acdlite](https://github.com/acdlite))
- Added an `initialValue` argument to `useDeferredValue()` hook ([#​27500](https://github.com/facebook/react/pull/27500), [#​27509](https://github.com/facebook/react/pull/27509), [#​27512](https://github.com/facebook/react/pull/27512), [#​27888](https://github.com/facebook/react/pull/27888), [#​27550](https://github.com/facebook/react/pull/27550) by [@​acdlite](https://github.com/acdlite))
- Support refs as props, warn on `element.ref` access ([#​28348](https://github.com/facebook/react/pull/28348), [#​28464](https://github.com/facebook/react/pull/28464), [#​28731](https://github.com/facebook/react/pull/28731) by [@​acdlite](https://github.com/acdlite))
- Support Custom Elements ([#​22184](https://github.com/facebook/react/pull/22184), [#​26524](https://github.com/facebook/react/pull/26524), [#​26523](https://github.com/facebook/react/pull/26523), [#​27511](https://github.com/facebook/react/pull/27511), [#​24541](https://github.com/facebook/react/pull/24541) by [@​josepharhar](https://github.com/josepharhar), [@​sebmarkbage](https://github.com/sebmarkbage), [@​gnoff](https://github.com/gnoff) and [@​eps1lon](https://github.com/eps1lon))
- Add ref cleanup function ([#​25686](https://github.com/facebook/react/pull/25686), [#​28883](https://github.com/facebook/react/pull/28883), [#​28910](https://github.com/facebook/react/pull/28910) by [@​sammy-SC](https://github.com/sammy-SC), [@​jackpope](https://github.com/jackpope), and [@​kassens](https://github.com/kassens))
- Sibling pre-rendering replaced by sibling pre-warming ([#​26380](https://github.com/facebook/react/pull/26380), [#​26549](https://github.com/facebook/react/pull/26549), [#​30761](https://github.com/facebook/react/pull/30761), [#​30800](https://github.com/facebook/react/pull/30800), [#​30762](https://github.com/facebook/react/pull/30762), [#​30879](https://github.com/facebook/react/pull/30879), [#​30934](https://github.com/facebook/react/pull/30934), [#​30952](https://github.com/facebook/react/pull/30952), [#​31056](https://github.com/facebook/react/pull/31056), [#​31452](https://github.com/facebook/react/pull/31452) by [@​sammy-SC](https://github.com/sammy-SC), [@​acdlite](https://github.com/acdlite), [@​gnoff](https://github.com/gnoff), [@​jackpope](https://github.com/jackpope), [@​rickhanlonii](https://github.com/rickhanlonii))
- Don’t rethrow errors at the root ([#​28627](https://github.com/facebook/react/pull/28627), [#​28641](https://github.com/facebook/react/pull/28641) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Batch sync discrete, continuous, and default lanes ([#​25700](https://github.com/facebook/react/pull/25700) by [@​tyao1](https://github.com/tyao1))
- Switch `<Context>` to mean `<Context.Provider>` ([#​28226](https://github.com/facebook/react/pull/28226) by [@​gaearon](https://github.com/gaearon))
- Changes to *StrictMode*
- Handle `info`, `group`, and `groupCollapsed` in *StrictMode* logging ([#​25172](https://github.com/facebook/react/pull/25172) by [@​timneutkens](https://github.com/timneutkens))
- Refs are now attached/detached/attached in *StrictMode* ([#​25049](https://github.com/facebook/react/pull/25049) by [@​sammy-SC](https://github.com/sammy-SC))
- Fix `useSyncExternalStore()` hydration in *StrictMode* ([#​26791](https://github.com/facebook/react/pull/26791) by [@​sophiebits](https://github.com/sophiebits))
- Always trigger `componentWillUnmount()` in *StrictMode* ([#​26842](https://github.com/facebook/react/pull/26842) by [@​tyao1](https://github.com/tyao1))
- Restore double invoking `useState()` and `useReducer()` initializer functions in *StrictMode* ([#​28248](https://github.com/facebook/react/pull/28248) by [@​eps1lon](https://github.com/eps1lon))
- Reuse memoized result from first pass ([#​25583](https://github.com/facebook/react/pull/25583) by [@​acdlite](https://github.com/acdlite))
- Fix `useId()` in *StrictMode* ([#​25713](https://github.com/facebook/react/pull/25713) by [@​gnoff](https://github.com/gnoff))
- Add component name to *StrictMode* error messages ([#​25718](https://github.com/facebook/react/pull/25718) by [@​sammy-SC](https://github.com/sammy-SC))
- Add support for rendering BigInt ([#​24580](https://github.com/facebook/react/pull/24580) by [@​eps1lon](https://github.com/eps1lon))
- `act()` no longer checks `shouldYield` which can be inaccurate in test environments ([#​26317](https://github.com/facebook/react/pull/26317) by [@​acdlite](https://github.com/acdlite))
- Warn when keys are spread with props ([#​25697](https://github.com/facebook/react/pull/25697), [#​26080](https://github.com/facebook/react/pull/26080) by [@​sebmarkbage](https://github.com/sebmarkbage) and [@​kassens](https://github.com/kassens))
- Generate sourcemaps for production build artifacts ([#​26446](https://github.com/facebook/react/pull/26446) by [@​markerikson](https://github.com/markerikson))
- Improve stack diffing algorithm ([#​27132](https://github.com/facebook/react/pull/27132) by [@​KarimP](https://github.com/KarimP))
- Suspense throttling lowered from 500ms to 300ms ([#​26803](https://github.com/facebook/react/pull/26803) by [@​acdlite](https://github.com/acdlite))
- Lazily propagate context changes ([#​20890](https://github.com/facebook/react/pull/20890) by [@​acdlite](https://github.com/acdlite) and [@​gnoff](https://github.com/gnoff))
- Immediately rerender pinged fiber ([#​25074](https://github.com/facebook/react/pull/25074) by [@​acdlite](https://github.com/acdlite))
- Move update scheduling to microtask ([#​26512](https://github.com/facebook/react/pull/26512) by [@​acdlite](https://github.com/acdlite))
- Consistently apply throttled retries ([#​26611](https://github.com/facebook/react/pull/26611), [#​26802](https://github.com/facebook/react/pull/26802) by [@​acdlite](https://github.com/acdlite))
- Suspend Thenable/Lazy if it's used in React.Children ([#​28284](https://github.com/facebook/react/pull/28284) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Detect infinite update loops caused by render phase updates ([#​26625](https://github.com/facebook/react/pull/26625) by [@​acdlite](https://github.com/acdlite))
- Update conditional hooks warning ([#​29626](https://github.com/facebook/react/pull/29626) by [@​sophiebits](https://github.com/sophiebits))
- Update error URLs to go to new docs ([#​27240](https://github.com/facebook/react/pull/27240) by [@​rickhanlonii](https://github.com/rickhanlonii))
- Rename the `react.element` symbol to `react.transitional.element` ([#​28813](https://github.com/facebook/react/pull/28813) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Fix crash when suspending in shell during `useSyncExternalStore()` re-render ([#​27199](https://github.com/facebook/react/pull/27199) by [@​acdlite](https://github.com/acdlite))
- Fix incorrect “detected multiple renderers" error in tests ([#​22797](https://github.com/facebook/react/pull/22797) by [@​eps1lon](https://github.com/eps1lon))
- Fix bug where effect cleanup may be called twice after bailout ([#​26561](https://github.com/facebook/react/pull/26561) by [@​acdlite](https://github.com/acdlite))
- Fix suspending in shell during discrete update ([#​25495](https://github.com/facebook/react/pull/25495) by [@​acdlite](https://github.com/acdlite))
- Fix memory leak after repeated setState bailouts ([#​25309](https://github.com/facebook/react/pull/25309) by [@​acdlite](https://github.com/acdlite))
- Fix `useSyncExternalStore()` dropped update when state is dispatched in render phase ([#​25578](https://github.com/facebook/react/pull/25578) by [@​pandaiolo](https://github.com/pandaiolo))
- Fix logging when rendering a lazy fragment ([#​30372](https://github.com/facebook/react/pull/30372) by [@​tom-sherman](https://github.com/tom-sherman))
- Remove string refs ([#​25383](https://github.com/facebook/react/pull/25383), [#​28322](https://github.com/facebook/react/pull/28322) by [@​eps1lon](https://github.com/eps1lon) and [@​acdlite](https://github.com/acdlite))
- Remove Legacy Context ([#​30319](https://github.com/facebook/react/issues/30319) by [@​kassens](https://github.com/kassens))
- Remove `RefreshRuntime.findAffectedHostInstances` ([#​30538](https://github.com/facebook/react/pull/30538) by [@​gaearon](https://github.com/gaearon))
- Remove client caching from `cache()` API ([#​27977](https://github.com/facebook/react/pull/27977), [#​28250](https://github.com/facebook/react/pull/28250) by [@​acdlite](https://github.com/acdlite) and [@​gnoff](https://github.com/gnoff))
- Remove `propTypes` ([#​28324](https://github.com/facebook/react/pull/28324), [#​28326](https://github.com/facebook/react/pull/28326) by [@​gaearon](https://github.com/gaearon))
- Remove `defaultProps` support, except for classes ([#​28733](https://github.com/facebook/react/pull/28733) by [@​acdlite](https://github.com/acdlite))
- Remove UMD builds ([#​28735](https://github.com/facebook/react/pull/28735) by [@​gnoff](https://github.com/gnoff))
- Remove delay for non-transition updates ([#​26597](https://github.com/facebook/react/pull/26597) by [@​acdlite](https://github.com/acdlite))
- Remove `createFactory` ([#​27798](https://github.com/facebook/react/pull/27798) by [@​kassens](https://github.com/kassens))
##### React DOM
- Adds Form Actions to handle form submission ([#​26379](https://github.com/facebook/react/pull/26379), [#​26674](https://github.com/facebook/react/pull/26674), [#​26689](https://github.com/facebook/react/pull/26689), [#​26708](https://github.com/facebook/react/pull/26708), [#​26714](https://github.com/facebook/react/pull/26714), [#​26735](https://github.com/facebook/react/pull/26735), [#​26846](https://github.com/facebook/react/pull/26846), [#​27358](https://github.com/facebook/react/pull/27358), [#​28056](https://github.com/facebook/react/pull/28056) by [@​sebmarkbage](https://github.com/sebmarkbage), [@​acdlite](https://github.com/acdlite), and [@​jupapios](https://github.com/jupapios))
- Add `useFormStatus()` hook to provide status information of the last form submission ([#​26719](https://github.com/facebook/react/pull/26719), [#​26722](https://github.com/facebook/react/pull/26722), [#​26788](https://github.com/facebook/react/pull/26788), [#​29019](https://github.com/facebook/react/pull/29019), [#​28728](https://github.com/facebook/react/pull/28728), [#​28413](https://github.com/facebook/react/pull/28413) by [@​acdlite](https://github.com/acdlite) and [@​eps1lon](https://github.com/eps1lon))
- Support for Document Metadata. Adds `preinit`, `preinitModule`, `preconnect`, `prefetchDNS`, `preload`, and `preloadModule` APIs.
- [#​25060](https://github.com/facebook/react/pull/25060), [#​25243](https://github.com/facebook/react/pull/25243), [#​25388](https://github.com/facebook/react/pull/25388), [#​25432](https://github.com/facebook/react/pull/25432), [#​25436](https://github.com/facebook/react/pull/25436), [#​25426](https://github.com/facebook/react/pull/25426), [#​25500](https://github.com/facebook/react/pull/25500), [#​25480](https://github.com/facebook/react/pull/25480), [#​25508](https://github.com/facebook/react/pull/25508), [#​25515](https://github.com/facebook/react/pull/25515), [#​25514](https://github.com/facebook/react/pull/25514), [#​25532](https://github.com/facebook/react/pull/25532), [#​25536](https://github.com/facebook/react/pull/25536), [#​25534](https://github.com/facebook/react/pull/25534), [#​25546](https://github.com/facebook/react/pull/25546), [#​25559](https://github.com/facebook/react/pull/25559), [#​25569](https://github.com/facebook/react/pull/25569), [#​25599](https://github.com/facebook/react/pull/25599), [#​25689](https://github.com/facebook/react/pull/25689), [#​26106](https://github.com/facebook/react/pull/26106), [#​26152](https://github.com/facebook/react/pull/26152), [#​26239](https://github.com/facebook/react/pull/26239), [#​26237](https://github.com/facebook/react/pull/26237), [#​26280](https://github.com/facebook/react/pull/26280), [#​26154](https://github.com/facebook/react/pull/26154), [#​26256](https://github.com/facebook/react/pull/26256), [#​26353](https://github.com/facebook/react/pull/26353), [#​26427](https://github.com/facebook/react/pull/26427), [#​26450](https://github.com/facebook/react/pull/26450), [#​26502](https://github.com/facebook/react/pull/26502), [#​26514](https://github.com/facebook/react/pull/26514), [#​26531](https://github.com/facebook/react/pull/26531), [#​26532](https://github.com/facebook/react/pull/26532), [#​26557](https://github.com/facebook/react/pull/26557), [#​26871](https://github.com/facebook/react/pull/26871), [#​26881](https://github.com/facebook/react/pull/26881), [#​26877](https://github.com/facebook/react/pull/26877), [#​26873](https://github.com/facebook/react/pull/26873), [#​26880](https://github.com/facebook/react/pull/26880), [#​26942](https://github.com/facebook/react/pull/26942), [#​26938](https://github.com/facebook/react/pull/26938), [#​26940](https://github.com/facebook/react/pull/26940), [#​26939](https://github.com/facebook/react/pull/26939), [#​27030](https://github.com/facebook/react/pull/27030), [#​27201](https://github.com/facebook/react/pull/27201), [#​27212](https://github.com/facebook/react/pull/27212), [#​27217](https://github.com/facebook/react/pull/27217), [#​27218](https://github.com/facebook/react/pull/27218), [#​27220](https://github.com/facebook/react/pull/27220), [#​27224](https://github.com/facebook/react/pull/27224), [#​27223](https://github.com/facebook/react/pull/27223), [#​27269](https://github.com/facebook/react/pull/27269), [#​27260](https://github.com/facebook/react/pull/27260), [#​27347](https://github.com/facebook/react/pull/27347), [#​27346](https://github.com/facebook/react/pull/27346), [#​27361](https://github.com/facebook/react/pull/27361), [#​27400](https://github.com/facebook/react/pull/27400), [#​27541](https://github.com/facebook/react/pull/27541), [#​27610](https://github.com/facebook/react/pull/27610), [#​28110](https://github.com/facebook/react/pull/28110), [#​29693](https://github.com/facebook/react/pull/29693), [#​29732](https://github.com/facebook/react/pull/29732), [#​29811](https://github.com/facebook/react/pull/29811), [#​27586](https://github.com/facebook/react/pull/27586), [#​28069](https://github.com/facebook/react/pull/28069) by [@​gnoff](https://github.com/gnoff), [@​sebmarkbage](https://github.com/sebmarkbage), [@​acdlite](https://github.com/acdlite), [@​kassens](https://github.com/kassens), [@​sokra](https://github.com/sokra), [@​sweetliquid](https://github.com/sweetliquid)
- Add `fetchPriority` to `<img>` and `<link>` ([#​25927](https://github.com/facebook/react/pull/25927) by [@​styfle](https://github.com/styfle))
- Add support for SVG `transformOrigin` prop ([#​26130](https://github.com/facebook/react/pull/26130) by [@​arav-ind](https://github.com/arav-ind))
- Add support for `onScrollEnd` event ([#​26789](https://github.com/facebook/react/pull/26789) by [@​devongovett](https://github.com/devongovett))
- Allow `<hr>` as child of `<select>` ([#​27632](https://github.com/facebook/react/pull/27632) by [@​SouSingh](https://github.com/SouSingh))
- Add support for Popover API ([#​27981](https://github.com/facebook/react/pull/27981) by [@​eps1lon](https://github.com/eps1lon))
- Add support for `inert` ([#​24730](https://github.com/facebook/react/pull/24730) by [@​eps1lon](https://github.com/eps1lon))
- Add support for `imageSizes` and `imageSrcSet` ([#​22550](https://github.com/facebook/react/pull/22550) by [@​eps1lon](https://github.com/eps1lon))
- Synchronously flush transitions in popstate events ([#​26025](https://github.com/facebook/react/pull/26025), [#​27559](https://github.com/facebook/react/pull/27559), [#​27505](https://github.com/facebook/react/pull/27505), [#​30759](https://github.com/facebook/react/pull/30759) by [@​tyao1](https://github.com/tyao1) and [@​acdlite](https://github.com/acdlite))
- `flushSync` exhausts queue even if something throws ([#​26366](https://github.com/facebook/react/pull/26366) by [@​acdlite](https://github.com/acdlite))
- Throw error if `react` and `react-dom` versions don’t match ([#​29236](https://github.com/facebook/react/pull/29236) by [@​acdlite](https://github.com/acdlite))
- Ensure `srcset` and `src` are assigned last on `<img>` instances ([#​30340](https://github.com/facebook/react/pull/30340) by [@​gnoff](https://github.com/gnoff))
- Javascript URLs are replaced with functions that throw errors ([#​26507](https://github.com/facebook/react/pull/26507), [#​29808](https://github.com/facebook/react/pull/29808) by [@​sebmarkbage](https://github.com/sebmarkbage) and [@​kassens](https://github.com/kassens))
- Treat toggle and beforetoggle as discrete events ([#​29176](https://github.com/facebook/react/pull/29176) by [@​eps1lon](https://github.com/eps1lon))
- Filter out empty `src` and `href` attributes (unless for `<a href=”” />`) ([#​18513](https://github.com/facebook/react/pull/18513), [#​28124](https://github.com/facebook/react/pull/28124) by [@​bvaughn](https://github.com/bvaughn) and [@​eps1lon](https://github.com/eps1lon))
- Fix unitless `scale` style property ([#​25601](https://github.com/facebook/react/pull/25601) by [@​JonnyBurger](https://github.com/JonnyBurger))
- Fix `onChange` error message for controlled `<select>` ([#​27740](https://github.com/facebook/react/pull/27740) by [@​Biki-das](https://github.com/Biki-das))
- Fix focus restore in child windows after element reorder ([#​30951](https://github.com/facebook/react/pull/30951) by [@​ling1726](https://github.com/ling1726))
- Remove `render`, `hydrate`, `findDOMNode`, `unmountComponentAtNode`, `unstable_createEventHandle`, `unstable_renderSubtreeIntoContainer`, and `unstable_runWithPriority`. Move `createRoot` and `hydrateRoot` to `react-dom/client`. ([#​28271](https://github.com/facebook/react/pull/28271) by [@​gnoff](https://github.com/gnoff))
- Remove `test-utils` ([#​28541](https://github.com/facebook/react/pull/28541) by [@​eps1lon](https://github.com/eps1lon))
- Remove `unstable_flushControlled` ([#​26397](https://github.com/facebook/react/pull/26397) by [@​kassens](https://github.com/kassens))
- Remove legacy mode ([#​28468](https://github.com/facebook/react/pull/28468) by [@​gnoff](https://github.com/gnoff))
- Remove `renderToStaticNodeStream()` ([#​28873](https://github.com/facebook/react/pull/28873) by [@​gnoff](https://github.com/gnoff))
- Remove `unstable_renderSubtreeIntoContainer` ([#​29771](https://github.com/facebook/react/pull/29771) by [@​kassens](https://github.com/kassens))
##### React DOM Server
- Stable release of React Server Components ([Many, many PRs](https://github.com/facebook/react/pulls?q=is%3Apr+is%3Aclosed+%5BFlight%5D+in%3Atitle+created%3A%3C2024-12-01+) by [@​sebmarkbage](https://github.com/sebmarkbage), [@​acdlite](https://github.com/acdlite), [@​gnoff](https://github.com/gnoff), [@​sammy-SC](https://github.com/sammy-SC), [@​gaearon](https://github.com/gaearon), [@​sophiebits](https://github.com/sophiebits), [@​unstubbable](https://github.com/unstubbable), [@​lubieowoce](https://github.com/lubieowoce))
- Support Server Actions ([#​26124](https://github.com/facebook/react/pull/26124), [#​26632](https://github.com/facebook/react/pull/26632), [#​27459](https://github.com/facebook/react/pull/27459) by [@​sebmarkbage](https://github.com/sebmarkbage) and [@​acdlite](https://github.com/acdlite))
- Changes to SSR
- Add external runtime which bootstraps hydration on the client for binary transparency ([#​25437](https://github.com/facebook/react/pull/25437), [#​26169](https://github.com/facebook/react/pull/26169), [#​25499](https://github.com/facebook/react/pull/25499) by [@​MofeiZ](https://github.com/mofeiZ) and [@​acdlite](https://github.com/acdlite))
- Support subresource integrity for `bootstrapScripts` and `bootstrapModules` ([#​25104](https://github.com/facebook/react/pull/25104) by [@​gnoff](https://github.com/gnoff))
- Fix null bytes written at text chunk boundaries ([#​26228](https://github.com/facebook/react/pull/26228) by [@​sophiebits](https://github.com/sophiebits))
- Fix logic around attribute serialization ([#​26526](https://github.com/facebook/react/pull/26526) by [@​gnoff](https://github.com/gnoff))
- Fix precomputed chunk cleared on Node 18 ([#​25645](https://github.com/facebook/react/pull/25645) by [@​feedthejim](https://github.com/feedthejim))
- Optimize end tag chunks ([#​27522](https://github.com/facebook/react/pull/27522) by [@​yujunjung](https://github.com/yujunjung))
- Gracefully handle suspending in DOM configs ([#​26768](https://github.com/facebook/react/pull/26768) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Check for nullish values on ReactCustomFormAction ([#​26770](https://github.com/facebook/react/pull/26770) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Preload `bootstrapModules`, `bootstrapScripts`, and update priority queue ([#​26754](https://github.com/facebook/react/pull/26754), [#​26753](https://github.com/facebook/react/pull/26753), [#​27190](https://github.com/facebook/react/pull/27190), [#​27189](https://github.com/facebook/react/pull/27189) by [@​gnoff](https://github.com/gnoff))
- Client render the nearest child or parent suspense boundary if replay errors or is aborted ([#​27386](https://github.com/facebook/react/pull/27386) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Don't bail out of flushing if we still have pending root tasks ([#​27385](https://github.com/facebook/react/pull/27385) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Ensure Resumable State is Serializable ([#​27388](https://github.com/facebook/react/pull/27388) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Remove extra render pass when reverting to client render ([#​26445](https://github.com/facebook/react/pull/26445) by [@​acdlite](https://github.com/acdlite))
- Fix unwinding context during selective hydration ([#​25876](https://github.com/facebook/react/pull/25876) by [@​tyao1](https://github.com/tyao1))
- Stop flowing and then abort if a stream is cancelled ([#​27405](https://github.com/facebook/react/pull/27405) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Pass cancellation reason to abort ([#​27536](https://github.com/facebook/react/pull/27536) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Add `onHeaders` entrypoint option ([#​27641](https://github.com/facebook/react/pull/27641), [#​27712](https://github.com/facebook/react/pull/27712) by [@​gnoff](https://github.com/gnoff))
- Escape `<style>` and `<script>` textContent to enable rendering inner content without dangerouslySetInnerHTML ([#​28870](https://github.com/facebook/react/pull/28870), [#​28871](https://github.com/facebook/react/pull/28871) by [@​gnoff](https://github.com/gnoff))
- Fallback to client replaying actions for Blob serialization ([#​28987](https://github.com/facebook/react/pull/28987) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Render Suspense fallback if boundary contains new stylesheet during sync update ([#​28965](https://github.com/facebook/react/pull/28965) by [@​gnoff](https://github.com/gnoff))
- Fix header length tracking ([#​30327](https://github.com/facebook/react/issues/30327) by [@​gnoff](https://github.com/gnoff))
- Use `srcset` to trigger load event on mount ([#​30351](https://github.com/facebook/react/issues/30351) by [@​gnoff](https://github.com/gnoff))
- Don't perform work when closing stream ([#​30497](https://github.com/facebook/react/issues/30497) by [@​gnoff](https://github.com/gnoff))
- Allow aborting during render ([#​30488](https://github.com/facebook/react/issues/30488), [#​30730](https://github.com/facebook/react/pull/30730) by [@​gnoff](https://github.com/gnoff))
- Start initial work immediately ([#​31079](https://github.com/facebook/react/issues/31079) by [@​gnoff](https://github.com/gnoff))
- A transition flowing into a dehydrated boundary no longer suspends when showing fallback ([#​27230](https://github.com/facebook/react/pull/27230) by [@​acdlite](https://github.com/acdlite))
- Fix selective hydration triggers false update loop error ([#​27439](https://github.com/facebook/react/pull/27439) by [@​acdlite](https://github.com/acdlite))
- Warn for Child Iterator of all types but allow Generator Components ([#​28853](https://github.com/facebook/react/pull/28853) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Include regular stack trace in serialized errors ([#​28684](https://github.com/facebook/react/pull/28684), [#​28738](https://github.com/facebook/react/pull/28738) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Aborting early no longer infinitely suspends ([#​24751](https://github.com/facebook/react/pull/24751) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Fix hydration warning suppression in text comparisons ([#​24784](https://github.com/facebook/react/pull/24784) by [@​gnoff](https://github.com/gnoff))
- Changes to error handling in SSR
- Add diffs to hydration warnings ([#​28502](https://github.com/facebook/react/pull/28502), [#​28512](https://github.com/facebook/react/pull/28512) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Make Error creation lazy ([#​24728](https://github.com/facebook/react/pull/24728) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Remove recoverable error when a sync update flows into a dehydrated boundary ([#​25692](https://github.com/facebook/react/pull/25692) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Don't "fix up" mismatched text content with suppressedHydrationWarning ([#​26391](https://github.com/facebook/react/pull/26391) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Fix component stacks in errors ([#​27456](https://github.com/facebook/react/pull/27456) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Add component stacks to `onError` ([#​27761](https://github.com/facebook/react/pull/27761), [#​27850](https://github.com/facebook/react/pull/27850) by [@​gnoff](https://github.com/gnoff) and [@​sebmarkbage](https://github.com/sebmarkbage))
- Throw hydration mismatch errors once ([#​28502](https://github.com/facebook/react/pull/28502) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Add Bun streaming server renderer ([#​25597](https://github.com/facebook/react/pull/25597) by [@​colinhacks](https://github.com/colinhacks))
- Add nonce support to bootstrap scripts ([#​26738](https://github.com/facebook/react/pull/26738) by [@​danieltott](https://github.com/danieltott))
- Add `crossorigin` support to bootstrap scripts ([#​26844](https://github.com/facebook/react/pull/26844) by [@​HenriqueLimas](https://github.com/HenriqueLimas))
- Support `nonce` and `fetchpriority` in preload links ([#​26826](https://github.com/facebook/react/pull/26826) by [@​liuyenwei](https://github.com/liuyenwei))
- Add `referrerPolicy` to `ReactDOM.preload()` ([#​27096](https://github.com/facebook/react/pull/27096) by [@​styfle](https://github.com/styfle))
- Add server condition for `react/jsx-dev-runtime` ([#​28921](https://github.com/facebook/react/pull/28921) by [@​himself65](https://github.com/himself65))
- Export version ([#​29596](https://github.com/facebook/react/pull/29596) by [@​unstubbable](https://github.com/unstubbable))
- Rename the secret export of Client and Server internals ([#​28786](https://github.com/facebook/react/pull/28786), [#​28789](https://github.com/facebook/react/pull/28789) by [@​sebmarkbage](https://github.com/sebmarkbage))
- Remove layout effect warning on server ([#​26395](https://github.com/facebook/react/pull/26395) by [@​rickhanlonii](https://github.com/rickhanlonii))
- Remove `errorInfo.digest` from `onRecoverableError` ([#​28222](https://github.com/facebook/react/pull/28222) by [@​gnoff](https://github.com/gnoff))
##### ReactTestRenderer
- Add deprecation error to `react-test-renderer` on web ([#​27903](https://github.com/facebook/react/pull/27903), [#​28904](https://github.com/facebook/react/pull/28904) by [@​jackpope](https://github.com/jackpope) and [@​acdlite](https://github.com/acdlite))
- Render with ConcurrentRoot on web ([#​28498](https://github.com/facebook/react/pull/28498) by [@​jackpope](https://github.com/jackpope))
- Remove `react-test-renderer/shallow` export ([#​25475](https://github.com/facebook/react/pull/25475), [#​28497](https://github.com/facebook/react/pull/28497) by [@​sebmarkbage](https://github.com/sebmarkbage) and [@​jackpope](https://github.com/jackpope))
##### React Reconciler
- Enable suspending commits without blocking render ([#​26398](https://github.com/facebook/react/pull/26398), [#​26427](https://github.com/facebook/react/pull/26427) by [@​acdlite](https://github.com/acdlite))
- Remove `prepareUpdate` ([#​26583](https://github.com/facebook/react/pull/26583), [#​27409](http://github.com/facebook/react/pull/27409) by [@​sebmarkbage](https://github.com/sebmarkbage) and [@​sophiebits](https://github.com/sophiebits))
##### React-Is
- Enable tree shaking ([#​27701](https://github.com/facebook/react/pull/27701) by [@​markerikson](https://github.com/markerikson))
- Remove `isConcurrentMode` and `isAsyncMode` methods ([#​28224](https://github.com/facebook/react/pull/28224) by [@​gaearon](https://github.com/gaearon))
##### useSyncExternalStore
- Remove React internals access ([#​29868](https://github.com/facebook/react/pull/29868) by [@​phryneas](https://github.com/phryneas))
- Fix stale selectors keeping previous store references ([#​25969](https://github.com/facebook/react/pull/25968) by [@​jellevoost](https://github.com/jellevoost))
</details>
---
### Configuration
📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).
🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.
♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 **Ignore**: Close this PR and you won't be reminded about these updates again.
---
- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box
---
This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOS45OS4wIiwidXBkYXRlZEluVmVyIjoiMzkuMTEzLjAiLCJ0YXJnZXRCcmFuY2giOiJtYWluIiwibGFiZWxzIjpbImRlcGVuZGVuY2llcyJdfQ==-->
Reviewed-on: https://git.tristess.app/alexandresoro/ouca-web/pulls/6
Reviewed-by: Alexandre Soro <code@soro.dev>
Co-authored-by: renovate <renovate@git.tristess.app>
Co-committed-by: renovate <renovate@git.tristess.app>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Adds a new option to
react-dom/serverentrypoints.onHeaders: (headers: Headers) => void(non node envs)onHeaders: (headers: { Link?: string }) => void(node envs)When any
renderTo...orprerender...function is called and this option is provided the supplied function will be called sometime on or before completion of the render with some preload link headers.When provided during a
renderTo...the callback will usually be called after the first pass at work. The idea here is we want to get a set of headers to start the browser loading well before the shell is ready. We don't wait for the shell because if we did we may as well send the preloads as tags in the HTML.When provided during a
prerender...the callback will be called after the entire prerender is complete. The idea here is we are not responding to a live request and it is preferable to capture as much as possible for preloading as Headers in case the prerender was unable to finish the shell.Currently the following resources are always preloaded as headers when the option is provided
Additionally if we are providing headers when the shell is incomplete (regardless of whether it is render or prerender) we will also include any stylesheet Resources (ones with a precedence prop)
There is a second option
maxHeadersLength?: numberwhich allows you to specify the maximum length of the header content in unicode code units. This is what you get when you read the length property of a string in javascript. It's improtant to note that this is not the same as the utf-8 byte length when these headers are serialized in a Response. The utf8 representation may be the same size, or larger but it will never be smaller.If you do not supply a
maxHeadersLengthwe defaul to2000. This was chosen as half the value of the max headers length supported by commonly known web servers and CDNs. many browser and web server can support significantly more headers than this so you can use this option to increase the headers limit. You can also of course use it to be even more conservative. Again it is important to keep in mind there is no direct translation between the max length and the bytelength and so if you want to stay under a certain byte length you need to be potentially more aggressive in the maxHeadersLength you choose.Conceptually
onHeaderscould be called more than once as new headers are discovered however if we haven't started flushing yet but since most APIs for the server including the web standard Response only allow you to set headers once the current implementation will only call it one time