Update react monorepo to v19 (major)
This MR contains the following updates:
Package | Type | Update | Change |
---|---|---|---|
@types/react (source) | dependencies | major | ^16.9.0 -> ^19.0.0 |
@types/react-dom (source) | dependencies | major | ^16.9.0 -> ^19.0.0 |
react (source) | dependencies | major | ^16.13.1 -> ^19.0.0 |
react-dom (source) | dependencies | major | ^16.13.1 -> ^19.0.0 |
Release Notes
facebook/react (react)
v19.0.0
Below is a list of all new features, APIs, deprecations, and breaking changes. Read React 19 release post and 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 tostartTransition
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 likefetch()
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 formaction
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 forforwardRef
. - 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 withuseFormStatus
. When a<form> action
succeeds, React will automatically reset the form for uncontrolled components. The form can be reset manually with the newrequestFormReset
API. -
<button> and <input> formAction
prop: Actions can be passed to theformAction
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
, andaction
. - 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
, andpreconnect
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
andprerenderToNodeStream
APIs for static site generation. They are designed to work with streaming environments like Node.js Streams and Web Streams. UnlikerenderToString
, 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 for how to support React Server Components.
Deprecations
- Deprecated:
element.ref
access: React 19 supports ref as a prop, so we’re deprecatingelement.ref
in favor ofelement.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 or @testing-library/react-native
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 for more details and guidance on codemodding.
React
- New JSX Transform is now required: We introduced a new JSX transform 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
andonCaughtError
methods tocreateRoot
andhydrateRoot
to customize this error handling. - Removed:
propTypes
: UsingpropTypes
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 supportdefaultProps
since there is no ES6 alternative. - Removed:
contextTypes
andgetChildContext
: Legacy Context for class components has been removed in favor of thecontextType
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, allcreateFactory
usage can be migrated to JSX components. - Removed:
react-test-renderer/shallow
: This has been a re-export of react-shallow-renderer since React 18. If needed, you can continue to use the third-party package directly. We recommend using @testing-library/react or @testing-library/react-native instead.
React DOM
- Removed:
react-dom/test-utils
: We’ve movedact
fromreact-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
andReactDOM.hydrateRoot
. - Removed:
unmountComponentAtNode
: Removed in favor ofroot.unmount()
. - Removed:
ReactDOM
.findDOMNode
: You can replaceReactDOM
.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 thedeferredValue
returned. - Support for Custom Elements: React 19 now passes all tests on Custom Elements Everywhere.
- StrictMode changes:
useMemo
anduseCallback
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.
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 matchuseState
,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 tounknown
instead ofany
if the element is typed asReactElement
- 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: MostuseReducer
usage should not require explicit type arguments.
For example,-useReducer<React.Reducer<State, Action>>(reducer) +useReducer(reducer)
-useReducer<React.Reducer<State, Action>>(reducer) +useReducer<State, Action>(reducer)
All Changes
React
- Add support for async Actions (#26621, #26726, #28078, #28097, #29226, #29618, #29670, #26716 by @acdlite and @sebmarkbage)
- Add
useActionState()
hook to update state based on the result of a Form Action (#27270, #27278, #27309, #27302, #27307, #27366, #27370, #27321, #27374, #27372, #27397, #27399, #27460, #28557, #27570, #27571, #28631, #28788, #29694, #29695, #29694, #29665, #28232, #28319 by @acdlite, @eps1lon, and @rickhanlonii) - Add
use()
API to read resources in render (#25084, #25202, #25207, #25214, #25226, #25247, #25539, #25538, #25537, #25543, #25561, #25620, #25615, #25922, #25641, #25634, #26232, #26536, #26739, #28233 by @acdlite, @MofeiZ, @sebmarkbage, @sophiebits, @eps1lon, and @hansottowirtz) - Add
useOptimistic()
hook to display mutated state optimistically during an async mutation (#26740, #26772, #27277, #27453, #27454, #27936 by @acdlite) - Added an
initialValue
argument touseDeferredValue()
hook (#27500, #27509, #27512, #27888, #27550 by @acdlite) - Support refs as props, warn on
element.ref
access (#28348, #28464, #28731 by @acdlite) - Support Custom Elements (#22184, #26524, #26523, #27511, #24541 by @josepharhar, @sebmarkbage, @gnoff and @eps1lon)
- Add ref cleanup function (#25686, #28883, #28910 by @sammy-SC, @jackpope, and @kassens)
- Sibling pre-rendering replaced by sibling pre-warming (#26380, #26549, #30761, #30800, #30762, #30879, #30934, #30952, #31056, #31452 by @sammy-SC, @acdlite, @gnoff, @jackpope, @rickhanlonii)
- Don’t rethrow errors at the root (#28627, #28641 by @sebmarkbage)
- Batch sync discrete, continuous, and default lanes (#25700 by @tyao1)
- Switch
<Context>
to mean<Context.Provider>
(#28226 by @gaearon) - Changes to StrictMode
- Handle
info
,group
, andgroupCollapsed
in StrictMode logging (#25172 by @timneutkens) - Refs are now attached/detached/attached in StrictMode (#25049 by @sammy-SC)
- Fix
useSyncExternalStore()
hydration in StrictMode (#26791 by @sophiebits) - Always trigger
componentWillUnmount()
in StrictMode (#26842 by @tyao1) - Restore double invoking
useState()
anduseReducer()
initializer functions in StrictMode (#28248 by @eps1lon) - Reuse memoized result from first pass (#25583 by @acdlite)
- Fix
useId()
in StrictMode (#25713 by @gnoff) - Add component name to StrictMode error messages (#25718 by @sammy-SC)
- Handle
- Add support for rendering BigInt (#24580 by @eps1lon)
-
act()
no longer checksshouldYield
which can be inaccurate in test environments (#26317 by @acdlite) - Warn when keys are spread with props (#25697, #26080 by @sebmarkbage and @kassens)
- Generate sourcemaps for production build artifacts (#26446 by @markerikson)
- Improve stack diffing algorithm (#27132 by @KarimP)
- Suspense throttling lowered from 500ms to 300ms (#26803 by @acdlite)
- Lazily propagate context changes (#20890 by @acdlite and @gnoff)
- Immediately rerender pinged fiber (#25074 by @acdlite)
- Move update scheduling to microtask (#26512 by @acdlite)
- Consistently apply throttled retries (#26611, #26802 by @acdlite)
- Suspend Thenable/Lazy if it's used in React.Children (#28284 by @sebmarkbage)
- Detect infinite update loops caused by render phase updates (#26625 by @acdlite)
- Update conditional hooks warning (#29626 by @sophiebits)
- Update error URLs to go to new docs (#27240 by @rickhanlonii)
- Rename the
react.element
symbol toreact.transitional.element
(#28813 by @sebmarkbage) - Fix crash when suspending in shell during
useSyncExternalStore()
re-render (#27199 by @acdlite) - Fix incorrect “detected multiple renderers" error in tests (#22797 by @eps1lon)
- Fix bug where effect cleanup may be called twice after bailout (#26561 by @acdlite)
- Fix suspending in shell during discrete update (#25495 by @acdlite)
- Fix memory leak after repeated setState bailouts (#25309 by @acdlite)
- Fix
useSyncExternalStore()
dropped update when state is dispatched in render phase (#25578 by @pandaiolo) - Fix logging when rendering a lazy fragment (#30372 by @tom-sherman)
- Remove string refs (#25383, #28322 by @eps1lon and @acdlite)
- Remove Legacy Context (#30319 by @kassens)
- Remove
RefreshRuntime.findAffectedHostInstances
(#30538 by @gaearon) - Remove client caching from
cache()
API (#27977, #28250 by @acdlite and @gnoff) - Remove
propTypes
(#28324, #28326 by @gaearon) - Remove
defaultProps
support, except for classes (#28733 by @acdlite) - Remove UMD builds (#28735 by @gnoff)
- Remove delay for non-transition updates (#26597 by @acdlite)
- Remove
createFactory
(#27798 by @kassens)
React DOM
- Adds Form Actions to handle form submission (#26379, #26674, #26689, #26708, #26714, #26735, #26846, #27358, #28056 by @sebmarkbage, @acdlite, and @jupapios)
- Add
useFormStatus()
hook to provide status information of the last form submission (#26719, #26722, #26788, #29019, #28728, #28413 by @acdlite and @eps1lon) - Support for Document Metadata. Adds
preinit
,preinitModule
,preconnect
,prefetchDNS
,preload
, andpreloadModule
APIs.- #25060, #25243, #25388, #25432, #25436, #25426, #25500, #25480, #25508, #25515, #25514, #25532, #25536, #25534, #25546, #25559, #25569, #25599, #25689, #26106, #26152, #26239, #26237, #26280, #26154, #26256, #26353, #26427, #26450, #26502, #26514, #26531, #26532, #26557, #26871, #26881, #26877, #26873, #26880, #26942, #26938, #26940, #26939, #27030, #27201, #27212, #27217, #27218, #27220, #27224, #27223, #27269, #27260, #27347, #27346, #27361, #27400, #27541, #27610, #28110, #29693, #29732, #29811, #27586, #28069 by @gnoff, @sebmarkbage, @acdlite, @kassens, @sokra, @sweetliquid
- Add
fetchPriority
to<img>
and<link>
(#25927 by @styfle) - Add support for SVG
transformOrigin
prop (#26130 by @arav-ind) - Add support for
onScrollEnd
event (#26789 by @devongovett) - Allow
<hr>
as child of<select>
(#27632 by @SouSingh) - Add support for Popover API (#27981 by @eps1lon)
- Add support for
inert
(#24730 by @eps1lon) - Add support for
imageSizes
andimageSrcSet
(#22550 by @eps1lon) - Synchronously flush transitions in popstate events (#26025, #27559, #27505, #30759 by @tyao1 and @acdlite)
-
flushSync
exhausts queue even if something throws (#26366 by @acdlite) - Throw error if
react
andreact-dom
versions don’t match (#29236 by @acdlite) - Ensure
srcset
andsrc
are assigned last on<img>
instances (#30340 by @gnoff) - Javascript URLs are replaced with functions that throw errors (#26507, #29808 by @sebmarkbage and @kassens)
- Treat toggle and beforetoggle as discrete events (#29176 by @eps1lon)
- Filter out empty
src
andhref
attributes (unless for<a href=”” />
) (#18513, #28124 by @bvaughn and @eps1lon) - Fix unitless
scale
style property (#25601 by @JonnyBurger) - Fix
onChange
error message for controlled<select>
(#27740 by @Biki-das) - Fix focus restore in child windows after element reorder (#30951 by @ling1726)
- Remove
render
,hydrate
,findDOMNode
,unmountComponentAtNode
,unstable_createEventHandle
,unstable_renderSubtreeIntoContainer
, andunstable_runWithPriority
. MovecreateRoot
andhydrateRoot
toreact-dom/client
. (#28271 by @gnoff) - Remove
test-utils
(#28541 by @eps1lon) - Remove
unstable_flushControlled
(#26397 by @kassens) - Remove legacy mode (#28468 by @gnoff)
- Remove
renderToStaticNodeStream()
(#28873 by @gnoff) - Remove
unstable_renderSubtreeIntoContainer
(#29771 by @kassens)
React DOM Server
- Stable release of React Server Components (Many, many MRs by @sebmarkbage, @acdlite, @gnoff, @sammy-SC, @gaearon, @sophiebits, @unstubbable, @lubieowoce)
- Support Server Actions (#26124, #26632, #27459 by @sebmarkbage and @acdlite)
- Changes to SSR
- Add external runtime which bootstraps hydration on the client for binary transparency (#25437, #26169, #25499 by @MofeiZ and @acdlite)
- Support subresource integrity for
bootstrapScripts
andbootstrapModules
(#25104 by @gnoff) - Fix null bytes written at text chunk boundaries (#26228 by @sophiebits)
- Fix logic around attribute serialization (#26526 by @gnoff)
- Fix precomputed chunk cleared on Node 18 (#25645 by @feedthejim)
- Optimize end tag chunks (#27522 by @yujunjung)
- Gracefully handle suspending in DOM configs (#26768 by @sebmarkbage)
- Check for nullish values on ReactCustomFormAction (#26770 by @sebmarkbage)
- Preload
bootstrapModules
,bootstrapScripts
, and update priority queue (#26754, #26753, #27190, #27189 by @gnoff) - Client render the nearest child or parent suspense boundary if replay errors or is aborted (#27386 by @sebmarkbage)
- Don't bail out of flushing if we still have pending root tasks (#27385 by @sebmarkbage)
- Ensure Resumable State is Serializable (#27388 by @sebmarkbage)
- Remove extra render pass when reverting to client render (#26445 by @acdlite)
- Fix unwinding context during selective hydration (#25876 by @tyao1)
- Stop flowing and then abort if a stream is cancelled (#27405 by @sebmarkbage)
- Pass cancellation reason to abort (#27536 by @sebmarkbage)
- Add
onHeaders
entrypoint option (#27641, #27712 by @gnoff) - Escape
<style>
and<script>
textContent to enable rendering inner content without dangerouslySetInnerHTML (#28870, #28871 by @gnoff) - Fallback to client replaying actions for Blob serialization (#28987 by @sebmarkbage)
- Render Suspense fallback if boundary contains new stylesheet during sync update (#28965 by @gnoff)
- Fix header length tracking (#30327 by @gnoff)
- Use
srcset
to trigger load event on mount (#30351 by @gnoff) - Don't perform work when closing stream (#30497 by @gnoff)
- Allow aborting during render (#30488, #30730 by @gnoff)
- Start initial work immediately (#31079 by @gnoff)
- A transition flowing into a dehydrated boundary no longer suspends when showing fallback (#27230 by @acdlite)
- Fix selective hydration triggers false update loop error (#27439 by @acdlite)
- Warn for Child Iterator of all types but allow Generator Components (#28853 by @sebmarkbage)
- Include regular stack trace in serialized errors (#28684, #28738 by @sebmarkbage)
- Aborting early no longer infinitely suspends (#24751 by @sebmarkbage)
- Fix hydration warning suppression in text comparisons (#24784 by @gnoff)
- Changes to error handling in SSR
- Add diffs to hydration warnings (#28502, #28512 by @sebmarkbage)
- Make Error creation lazy (#24728 by @sebmarkbage)
- Remove recoverable error when a sync update flows into a dehydrated boundary (#25692 by @sebmarkbage)
- Don't "fix up" mismatched text content with suppressedHydrationWarning (#26391 by @sebmarkbage)
- Fix component stacks in errors (#27456 by @sebmarkbage)
- Add component stacks to
onError
(#27761, #27850 by @gnoff and @sebmarkbage) - Throw hydration mismatch errors once (#28502 by @sebmarkbage)
- Add Bun streaming server renderer (#25597 by @colinhacks)
- Add nonce support to bootstrap scripts (#26738 by @danieltott)
- Add
crossorigin
support to bootstrap scripts (#26844 by @HenriqueLimas) - Support
nonce
andfetchpriority
in preload links (#26826 by @liuyenwei) - Add
referrerPolicy
toReactDOM.preload()
(#27096 by @styfle) - Add server condition for
react/jsx-dev-runtime
(#28921 by @himself65) - Export version (#29596 by @unstubbable)
- Rename the secret export of Client and Server internals (#28786, #28789 by @sebmarkbage)
- Remove layout effect warning on server (#26395 by @rickhanlonii)
- Remove
errorInfo.digest
fromonRecoverableError
(#28222 by @gnoff)
ReactTestRenderer
- Add deprecation error to
react-test-renderer
on web (#27903, #28904 by @jackpope and @acdlite) - Render with ConcurrentRoot on web (#28498 by @jackpope)
- Remove
react-test-renderer/shallow
export (#25475, #28497 by @sebmarkbage and @jackpope)
React Reconciler
- Enable suspending commits without blocking render (#26398, #26427 by @acdlite)
- Remove
prepareUpdate
(#26583, #27409 by @sebmarkbage and @sophiebits)
React-Is
- Enable tree shaking (#27701 by @markerikson)
- Remove
isConcurrentMode
andisAsyncMode
methods (#28224 by @gaearon)
useSyncExternalStore
- Remove React internals access (#29868 by @phryneas)
- Fix stale selectors keeping previous store references (#25969 by @jellevoost)
v18.3.1
- Export
act
fromreact
f1338f
v18.3.0
This release is identical to 18.2 but adds warnings for deprecated APIs and other changes that are needed for React 19.
Read the React 19 Upgrade Guide for more info.
React
- Allow writing to
this.refs
to support string ref codemod 909071 - Warn for deprecated
findDOMNode
outside StrictMode c3b283 - Warn for deprecated
test-utils
methods d4ea75 - Warn for deprecated Legacy Context outside StrictMode 415ee0
- Warn for deprecated string refs outside StrictMode #25383
- Warn for deprecated
defaultProps
for function components #25699 - Warn when spreading
key
#25697 - Warn when using
act
fromtest-utils
d4ea75
React DOM
- Warn for deprecated
unmountComponentAtNode
8a015b - Warn for deprecated
renderToStaticNodeStream
#28874
v18.2.0
React DOM
- Provide a component stack as a second argument to
onRecoverableError
. (@gnoff in #24591) - Fix hydrating into
document
causing a blank page on mismatch. (@gnoff in #24523) - Fix false positive hydration errors with Suspense. (@gnoff in #24480 and @acdlite in #24532)
- Fix ignored
setState
in Safari when adding an iframe. (@gaearon in #24459)
React DOM Server
- Pass information about server errors to the client. (@salazarm and @gnoff in #24551 and #24591)
- Allow to provide a reason when aborting the HTML stream. (@gnoff in #24680)
- Eliminate extraneous text separators in the HTML where possible. (@gnoff in #24630)
- Disallow complex children inside
<title>
elements to match the browser constraints. (@gnoff in #24679) - Fix buffering in some worker environments by explicitly setting
highWaterMark
to0
. (@jplhomer in #24641)
Server Components (Experimental)
v18.1.0
React DOM
- Fix the false positive warning about
react-dom/client
when using UMD bundle. (@alireza-molaee in #24274) - Fix
suppressHydrationWarning
to work in production too. (@gaearon in #24271) - Fix
componentWillUnmount
firing twice inside of Suspense. (@acdlite in #24308) - Fix some transition updates being ignored. (@acdlite in #24353)
- Fix
useDeferredValue
causing an infinite loop when passed an unmemoized value. (@acdlite in #24247) - Fix throttling of revealing Suspense fallbacks. (@sunderls in #24253)
- Fix an inconsistency in whether the props object is the same between renders. (@Andarist and @acdlite in #24421)
- Fix a missing warning about a
setState
loop inuseEffect
. (@gaearon in #24298) - Fix a spurious hydration error. (@gnoff in #24404)
- Warn when calling
setState
inuseInsertionEffect
. (@gaearon in #24295) - Ensure the reason for hydration errors is always displayed. (@gaearon in #24276)
React DOM Server
- Fix escaping for the
bootstrapScriptContent
contents. (@gnoff in #24385) - Significantly improve performance of
renderToPipeableStream
. (@gnoff in #24291)
ESLint Plugin: React Hooks
- Fix false positive errors with a large number of branches. (@scyron6 in #24287)
- Don't consider a known dependency stable when the variable is reassigned. (@afzalsayed96 in #24343)
Use Subscription
v18.0.0
Below is a list of all new features, APIs, deprecations, and breaking changes. Read React 18 release post and React 18 upgrade guide for more information.
New Features
React
-
useId
is a new hook for generating unique IDs on both the client and server, while avoiding hydration mismatches. It is primarily useful for component libraries integrating with accessibility APIs that require unique IDs. This solves an issue that already exists in React 17 and below, but it’s even more important in React 18 because of how the new streaming server renderer delivers HTML out-of-order. -
startTransition
anduseTransition
let you mark some state updates as not urgent. Other state updates are considered urgent by default. React will allow urgent state updates (for example, updating a text input) to interrupt non-urgent state updates (for example, rendering a list of search results). -
useDeferredValue
lets you defer re-rendering a non-urgent part of the tree. It is similar to debouncing, but has a few advantages compared to it. There is no fixed time delay, so React will attempt the deferred render right after the first render is reflected on the screen. The deferred render is interruptible and doesn't block user input. -
useSyncExternalStore
is a new hook that allows external stores to support concurrent reads by forcing updates to the store to be synchronous. It removes the need foruseEffect
when implementing subscriptions to external data sources, and is recommended for any library that integrates with state external to React. -
useInsertionEffect
is a new hook that allows CSS-in-JS libraries to address performance issues of injecting styles in render. Unless you’ve already built a CSS-in-JS library we don’t expect you to ever use this. This hook will run after the DOM is mutated, but before layout effects read the new layout. This solves an issue that already exists in React 17 and below, but is even more important in React 18 because React yields to the browser during concurrent rendering, giving it a chance to recalculate layout.
React DOM Client
These new APIs are now exported from react-dom/client
:
-
createRoot
: New method to create a root torender
orunmount
. Use it instead ofReactDOM.render
. New features in React 18 don't work without it. -
hydrateRoot
: New method to hydrate a server rendered application. Use it instead ofReactDOM.hydrate
in conjunction with the new React DOM Server APIs. New features in React 18 don't work without it.
Both createRoot
and hydrateRoot
accept a new option called onRecoverableError
in case you want to be notified when React recovers from errors during rendering or hydration for logging. By default, React will use reportError
, or console.error
in the older browsers.
React DOM Server
These new APIs are now exported from react-dom/server
and have full support for streaming Suspense on the server:
-
renderToPipeableStream
: for streaming in Node environments. -
renderToReadableStream
: for modern edge runtime environments, such as Deno and Cloudflare workers.
The existing renderToString
method keeps working but is discouraged.
v17.0.2
React DOM
- Remove an unused dependency to address the
SharedArrayBuffer
cross-origin isolation warning. (@koba04 and @bvaughn in #20831, #20832, and #20840)
v17.0.1
React DOM
v17.0.0
Today, we are releasing React 17!
Learn more about React 17 and how to update to it on the official React blog.
React
- Add
react/jsx-runtime
andreact/jsx-dev-runtime
for the new JSX transform. (@lunaruan in #18299) - Build component stacks from native error frames. (@sebmarkbage in #18561)
- Allow to specify
displayName
on context for improved stacks. (@eps1lon in #18224) - Prevent
'use strict'
from leaking in the UMD bundles. (@koba04 in #19614) - Stop using
fb.me
for redirects. (@cylim in #19598)
React DOM
- Delegate events to roots instead of
document
. (@trueadm in #18195 and others) - Clean up all effects before running any next effects. (@bvaughn in #17947)
- Run
useEffect
cleanup functions asynchronously. (@bvaughn in #17925) - Use browser
focusin
andfocusout
foronFocus
andonBlur
. (@trueadm in #19186) - Make all
Capture
events use the browser capture phase. (@trueadm in #19221) - Don't emulate bubbling of the
onScroll
event. (@gaearon in #19464) - Throw if
forwardRef
ormemo
component returnsundefined
. (@gaearon in #19550) - Remove event pooling. (@trueadm in #18969)
- Stop exposing internals that won’t be needed by React Native Web. (@necolas in #18483)
- Attach all known event listeners when the root mounts. (@gaearon in #19659)
- Disable
console
in the second render pass of DEV mode double render. (@sebmarkbage in #18547) - Deprecate the undocumented and misleading
ReactTestUtils.SimulateNative
API. (@gaearon in #13407) - Rename private field names used in the internals. (@gaearon in #18377)
- Don't call User Timing API in development. (@gaearon in #18417)
- Disable console during the repeated render in Strict Mode. (@sebmarkbage in #18547)
- In Strict Mode, double-render components without Hooks too. (@eps1lon in #18430)
- Allow calling
ReactDOM.flushSync
during lifecycle methods (but warn). (@sebmarkbage in #18759) - Add the
code
property to the keyboard event objects. (@bl00mber in #18287) - Add the
disableRemotePlayback
property forvideo
elements. (@tombrowndev in #18619) - Add the
enterKeyHint
property forinput
elements. (@eps1lon in #18634) - Warn when no
value
is provided to<Context.Provider>
. (@charlie1404 in #19054) - Warn when
memo
orforwardRef
components returnundefined
. (@bvaughn in #19550) - Improve the error message for invalid updates. (@JoviDeCroock in #18316)
- Exclude forwardRef and memo from stack frames. (@sebmarkbage in #18559)
- Improve the error message when switching between controlled and uncontrolled inputs. (@vcarl in #17070)
- Keep
onTouchStart
,onTouchMove
, andonWheel
passive. (@gaearon in #19654) - Fix
setState
hanging in development inside a closed iframe. (@gaearon in #19220) - Fix rendering bailout for lazy components with
defaultProps
. (@jddxf in #18539) - Fix a false positive warning when
dangerouslySetInnerHTML
isundefined
. (@eps1lon in #18676) - Fix Test Utils with non-standard
require
implementation. (@just-boris in #18632) - Fix
onBeforeInput
reporting an incorrectevent.type
. (@eps1lon in #19561) - Fix
event.relatedTarget
reported asundefined
in Firefox. (@claytercek in #19607) - Fix "unspecified error" in IE11. (@hemakshis in #19664)
- Fix rendering into a shadow root. (@Jack-Works in #15894)
- Fix
movementX/Y
polyfill with capture events. (@gaearon in #19672) - Use delegation for
onSubmit
andonReset
events. (@gaearon in #19333) - Improve memory usage. (@trueadm in #18970)
React DOM Server
- Make
useCallback
behavior consistent withuseMemo
for the server renderer. (@alexmckenley in #18783) - Fix state leaking when a function component throws. (@pmaccart in #19212)
React Test Renderer
- Improve
findByType
error message. (@henryqdineen in #17439)
Concurrent Mode (Experimental)
- Revamp the priority batching heuristics. (@acdlite in #18796)
- Add the
unstable_
prefix before the experimental APIs. (@acdlite in #18825) - Remove
unstable_discreteUpdates
andunstable_flushDiscreteUpdates
. (@trueadm in #18825) - Remove the
timeoutMs
argument. (@acdlite in #19703) - Disable
<div hidden />
prerendering in favor of a different future API. (@acdlite in #18917) - Add
unstable_expectedLoadTime
to Suspense for CPU-bound trees. (@acdlite in #19936) - Add an experimental
unstable_useOpaqueIdentifier
Hook. (@lunaruan in #17322) - Add an experimental
unstable_startTransition
API. (@rickhanlonii in #19696) - Using
act
in the test renderer no longer flushes Suspense fallbacks. (@acdlite in #18596) - Use global render timeout for CPU Suspense. (@sebmarkbage in #19643)
- Clear the existing root content before mounting. (@bvaughn in #18730)
- Fix a bug with error boundaries. (@acdlite in #18265)
- Fix a bug causing dropped updates in a suspended tree. (@acdlite in #18384 and #18457)
- Fix a bug causing dropped render phase updates. (@acdlite in #18537)
- Fix a bug in SuspenseList. (@sebmarkbage in #18412)
- Fix a bug causing Suspense fallback to show too early. (@acdlite in #18411)
- Fix a bug with class components inside SuspenseList. (@sebmarkbage in #18448)
- Fix a bug with inputs that may cause updates to be dropped. (@jddxf in #18515 and @acdlite in #18535)
- Fix a bug causing Suspense fallback to get stuck. (@acdlite in #18663)
- Don't cut off the tail of a SuspenseList if hydrating. (@sebmarkbage in #18854)
- Fix a bug in
useMutableSource
that may happen whengetSnapshot
changes. (@bvaughn in #18297) - Fix a tearing bug in
useMutableSource
. (@bvaughn in #18912) - Warn if calling setState outside of render but before commit. (@sebmarkbage in #18838)
v16.14.0
React
- Add support for the new JSX transform. (@lunaruan in #18299)
Configuration
-
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