react-dom

React DOM

• Remove an unused dependency to address the SharedArrayBuffer cross-origin isolation warning. (@koba04 and @bvaughn in #20831, #20832, and #20840)

Artifacts

• react: https://unpkg.com/react@17.0.2/umd/
• react-art: https://unpkg.com/react-art@17.0.2/umd/
• react-dom: https://unpkg.com/react-dom@17.0.2/umd/
• react-is: https://unpkg.com/react-is@17.0.2/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@17.0.2/umd/
• scheduler: https://unpkg.com/scheduler@0.20.2/umd/

React DOM

• Fix a crash in IE11. (@gaearon in #20071)

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 and react/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 and focusout for onFocus and onBlur. (@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 or memo component returns undefined. (@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 for video elements. (@tombrowndev in #18619)
• Add the enterKeyHint property for input elements. (@eps1lon in #18634)
• Warn when no value is provided to <Context.Provider>. (@charlie1404 in #19054)
• Warn when memo or forwardRef components return undefined. (@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, and onWheel 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 is undefined. (@eps1lon in #18676)
• Fix Test Utils with non-standard require implementation. (@just-boris in #18632)
• Fix onBeforeInput reporting an incorrect event.type. (@eps1lon in #19561)
• Fix event.relatedTarget reported as undefined 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 and onReset events. (@gaearon in #19333)
• Improve memory usage. (@trueadm in #18970)

React DOM Server

• Make useCallback behavior consistent with useMemo 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 and unstable_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 when getSnapshot 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)

Artifacts

• react: https://unpkg.com/react@17.0.1/umd/
• react-art: https://unpkg.com/react-art@17.0.1/umd/
• react-dom: https://unpkg.com/react-dom@17.0.1/umd/
• react-is: https://unpkg.com/react-is@17.0.1/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@17.0.1/umd/
• scheduler: https://unpkg.com/scheduler@0.20.1/umd/

React

• Add support for the new JSX transform. (@lunaruan in #18299)

React DOM

• Fix bug in legacy mode Suspense where effect clean-up functions are not fired. This only affects users who use Suspense for data fetching in legacy mode, which is not technically supported. (@acdlite in #18238)
• Revert warning for cross-component updates that happen inside class render lifecycles (componentWillReceiveProps, shouldComponentUpdate, and so on). (@gaearon in #18330)

Artifacts

• react: https://unpkg.com/react@16.13.1/umd/
• react-art: https://unpkg.com/react-art@16.13.1/umd/
• react-dom: https://unpkg.com/react-dom@16.13.1/umd/
• react-is: https://unpkg.com/react-is@16.13.1/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.13.1/umd/
• scheduler: https://unpkg.com/scheduler@0.19.1/umd/

React

• Warn when a string ref is used in a manner that's not amenable to a future codemod (@lunaruan in #17864)
• Deprecate React.createFactory() (@trueadm in #17878)

React DOM

• Warn when changes in style may cause an unexpected collision (@sophiebits in #14181, #18002)
• Warn when a function component is updated during another component's render phase (@acdlite in #17099)
• Deprecate unstable_createPortal (@trueadm in #17880)
• Fix onMouseEnter being fired on disabled buttons (@AlfredoGJ in #17675)
• Call shouldComponentUpdate twice when developing in StrictMode (@bvaughn in #17942)
• Add version property to ReactDOM (@ealush in #15780)
• Don't call toString() of dangerouslySetInnerHTML (@sebmarkbage in #17773)
• Show component stacks in more warnings (@gaearon in #17922, #17586)

Concurrent Mode (Experimental)

• Warn for problematic usages of ReactDOM.createRoot() (@trueadm in #17937)
• Remove ReactDOM.createRoot() callback params and added warnings on usage (@bvaughn in #17916)
• Don't group Idle/Offscreen work with other work (@sebmarkbage in #17456)
• Adjust SuspenseList CPU bound heuristic (@sebmarkbage in #17455)
• Add missing event plugin priorities (@trueadm in #17914)
• Fix isPending only being true when transitioning from inside an input event (@acdlite in #17382)
• Fix React.memo components dropping updates when interrupted by a higher priority update (@acdlite in #18091)
• Don't warn when suspending at the wrong priority (@gaearon in #17971)
• Fix a bug with rebasing updates (@acdlite and @sebmarkbage in #17560, #17510, #17483, #17480)

Artifacts

• react: https://unpkg.com/react@16.13.0/umd/
• react-art: https://unpkg.com/react-art@16.13.0/umd/
• react-dom: https://unpkg.com/react-dom@16.13.0/umd/
• react-is: https://unpkg.com/react-is@16.13.0/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.13.0/umd/
• scheduler: https://unpkg.com/scheduler@0.19.0/umd/

React DOM

• Fix passive effects (useEffect) not being fired in a multi-root app. (@acdlite in #17347)

React Is

• Fix lazy and memo types considered elements instead of components (@bvaughn in #17278)

Artifacts

• react: https://unpkg.com/react@16.12.0/umd/ • react-art: https://unpkg.com/react-art@16.12.0/umd/ • react-dom: https://unpkg.com/react-dom@16.12.0/umd/ • react-is: https://unpkg.com/react-is@16.12.0/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.12.0/umd/ • scheduler: https://unpkg.com/scheduler@0.18.0/umd/

React DOM

• Fix mouseenter handlers from firing twice inside nested React containers. @yuanoook in #16928
• Remove unstable_createRoot and unstable_createSyncRoot experimental APIs. (These are available in the Experimental channel as createRoot and createSyncRoot.) (@acdlite in #17088)

Artifacts

• react: https://unpkg.com/react@16.11.0/umd/ • react-art: https://unpkg.com/react-art@16.11.0/umd/ • react-dom: https://unpkg.com/react-dom@16.11.0/umd/ • react-is: https://unpkg.com/react-is@16.11.0/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.11.0/umd/ • scheduler: https://unpkg.com/scheduler@0.17.0/umd/

React DOM

• Fix regression in react-native-web by restoring order of arguments in event plugin extractors (@necolas in #16978)

Artifacts

• react: https://unpkg.com/react@16.10.2/umd/ • react-art: https://unpkg.com/react-art@16.10.2/umd/ • react-dom: https://unpkg.com/react-dom@16.10.2/umd/ • react-is: https://unpkg.com/react-is@16.10.2/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.10.2/umd/ • scheduler: https://unpkg.com/scheduler@0.16.2/umd/

React DOM

• Fix regression in Next.js apps by allowing Suspense mismatch during hydration to silently proceed (@sebmarkbage in #16943)

React DOM

• Fix edge case where a hook update wasn't being memoized. (@sebmarkbage in #16359)
• Fix heuristic for determining when to hydrate, so we don't incorrectly hydrate during an update. (@sebmarkbage in #16739)
• Clear additional fiber fields during unmount to save memory. (@trueadm in #16807)
• Fix bug with required text fields in Firefox. (@halvves in #16578)
• Prefer Object.is instead of inline polyfill, when available. (@ku8ar in #16212)
• Fix bug when mixing Suspense and error handling. (@acdlite in #16801)

Scheduler (Experimental)

• Improve queue performance by switching its internal data structure to a min binary heap. (@acdlite in #16245)
• Use postMessage loop with short intervals instead of attempting to align to frame boundaries with requestAnimationFrame. (@acdlite in #16214)

useSubscription

• Avoid tearing issue when a mutation happens and the previous update is still in progress. (@bvaughn in #16623)

Artifacts

• react: https://unpkg.com/react@16.10.0/umd/ • react-art: https://unpkg.com/react-art@16.10.0/umd/ • react-dom: https://unpkg.com/react-dom@16.10.0/umd/ • react-is: https://unpkg.com/react-is@16.10.0/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.10.0/umd/ • scheduler: https://unpkg.com/scheduler@0.16.0/umd/

React

• Add <React.Profiler> API for gathering performance measurements programmatically. (@bvaughn in #15172)
• Remove unstable_ConcurrentMode in favor of unstable_createRoot. (@acdlite in #15532)

React DOM

• Deprecate old names for the UNSAFE_* lifecycle methods. (@bvaughn in #15186 and @threepointone in #16103)
• Deprecate javascript: URLs as a common attack surface. (@sebmarkbage in #15047)
• Deprecate uncommon "module pattern" (factory) components. (@sebmarkbage in #15145)
• Add support for the disablePictureInPicture attribute on <video>. (@eek in #15334)
• Add support for onLoad event for <embed>. (@cherniavskii in #15614)
• Add support for editing useState state from DevTools. (@bvaughn in #14906)
• Add support for toggling Suspense from DevTools. (@gaearon in #15232)
• Warn when setState is called from useEffect, creating a loop. (@gaearon in #15180)
• Fix a memory leak. (@paulshen in #16115)
• Fix a crash inside findDOMNode for components wrapped in <Suspense>. (@acdlite in #15312)
• Fix pending effects from being flushed too late. (@acdlite in #15650)
• Fix incorrect argument order in a warning message. (@brickspert in #15345)
• Fix hiding Suspense fallback nodes when there is an !important style. (@acdlite in #15861 and #15882)
• Slightly improve hydration performance. (@bmeurer in #15998)

React DOM Server

• Fix incorrect output for camelCase custom CSS property names. (@bedakb in #16167)

React Test Utilities and Test Renderer

• Add act(async () => ...) for testing asynchronous state updates. (@threepointone in #14853)
• Add support for nesting act from different renderers. (@threepointone in #16039 and #16042)
• Warn in Strict Mode if effects are scheduled outside an act() call. (@threepointone in #15763 and #16041)
• Warn when using act from the wrong renderer. (@threepointone in #15756)

Artifacts

• react: https://unpkg.com/react@16.9.0/umd/ • react-art: https://unpkg.com/react-art@16.9.0/umd/ • react-dom: https://unpkg.com/react-dom@16.9.0/umd/ • react-is: https://unpkg.com/react-is@16.9.0/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.9.0/umd/ • scheduler: https://unpkg.com/scheduler@0.15.0/umd/

This is a release candidate for React v16.9.0.

Changelog is available in https://github.com/facebook/react/pull/16254.

UMD builds

• react: https://unpkg.com/react@16.9.0-rc.0/umd/ • react-art: https://unpkg.com/react-art@16.9.0-rc.0/umd/ • react-dom: https://unpkg.com/react-dom@16.9.0-rc.0/umd/ • react-is: https://unpkg.com/react-is@16.9.0-rc.0/umd/ • react-test-renderer: https://unpkg.com/react-test-renderer@16.9.0-rc.0/umd/ • scheduler: https://unpkg.com/scheduler@0.15.0-rc.0/umd/

v16.9.0-alpha.0 (April 3, 2019)

• (await act(async () => ...) (@threepointone in #14853)

Artifacts

• react: https://unpkg.com/react@16.9.0-alpha.0/umd/
• react-art: https://unpkg.com/react-art@16.9.0-alpha.0/umd/
• react-dom: https://unpkg.com/react-dom@16.9.0-alpha.0/umd/
• react-is: https://unpkg.com/react-is@16.9.0-alpha.0/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.9.0-alpha.0/umd/
• scheduler: https://unpkg.com/scheduler@0.14.0-alpha.0/umd/

16.8.6 (March 27, 2019)

React DOM

• Fix an incorrect bailout in useReducer(). (@acdlite in #15124)
• Fix iframe warnings in Safari DevTools. (@renanvalentin in #15099)
• Warn if contextType is set to Context.Consumer instead of Context. (@aweary in #14831)
• Warn if contextType is set to invalid values. (@gaearon in #15142)

Artifacts

• react: https://unpkg.com/react@16.8.6/umd/
• react-art: https://unpkg.com/react-art@16.8.6/umd/
• react-dom: https://unpkg.com/react-dom@16.8.6/umd/
• react-is: https://unpkg.com/react-is@16.8.6/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.6/umd/
• scheduler: https://unpkg.com/scheduler@0.13.6/umd/

16.8.5 (March 22, 2019)

React DOM

• Don't set the first option as selected in select tag with size attribute. (@kulek1 in #14242)
• Improve the useEffect(async () => ...) warning message. (@gaearon in #15118)
• Improve the error message sometimes caused by duplicate React. (@jaredpalmer in #15139)

React DOM Server

• Improve the useLayoutEffect warning message when server rendering. (@gaearon in #15158)

React Shallow Renderer

• Fix setState in shallow renderer to work with Hooks. (@gaearon in #15120)
• Fix shallow renderer to support React.memo. (@aweary in #14816)
• Fix shallow renderer to support Hooks inside forwardRef. (@eps1lon in #15100)

Artifacts

• react: https://unpkg.com/react@16.8.5/umd/
• react-art: https://unpkg.com/react-art@16.8.5/umd/
• react-dom: https://unpkg.com/react-dom@16.8.5/umd/
• react-is: https://unpkg.com/react-is@16.8.5/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.5/umd/
• scheduler: https://unpkg.com/scheduler@0.13.5/umd/

16.8.4 (March 5, 2019)

React DOM and other renderers

• Fix a bug where DevTools caused a runtime error when inspecting a component that used a useContext hook. (@bvaughn in #14940)

16.8.3 (February 21, 2019)

React DOM

• Fix a bug that caused inputs to behave incorrectly in UMD builds. (@gaearon in #14914)
• Fix a bug that caused render phase updates to be discarded. (@gaearon in #14852)

React DOM Server

• Unwind the context stack when a stream is destroyed without completing, to prevent incorrect values during a subsequent render. (@overlookmotel in #14706)

ESLint Plugin for React Hooks

• Add a new recommended exhaustive-deps rule. (@gaearon in #14636)

Artifacts

• react: https://unpkg.com/react@16.8.3/umd/
• react-art: https://unpkg.com/react-art@16.8.3/umd/
• react-dom: https://unpkg.com/react-dom@16.8.3/umd/
• react-is: https://unpkg.com/react-is@16.8.3/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.3/umd/
• scheduler: https://unpkg.com/scheduler@0.13.3/umd/

16.8.2 (February 14, 2019)

React DOM

• Fix ReactDOM.render being ignored inside useEffect. (@gaearon in #14799)
• Fix a crash when unmounting empty portals. (@gaearon in #14820)
• Fix useImperativeHandle to work correctly when no deps are specified. (@gaearon in #14801)
• Fix crossOrigin attribute to work in SVG image elements. (@aweary in #14832)
• Fix a false positive warning when using Suspense with Hooks. (@gaearon in #14821)

React Test Utils and React Test Renderer

• Include component stack into the act() warning. (@threepointone in #14855)

Artifacts

• react: https://unpkg.com/react@16.8.2/umd/
• react-art: https://unpkg.com/react-art@16.8.2/umd/
• react-dom: https://unpkg.com/react-dom@16.8.2/umd/
• react-is: https://unpkg.com/react-is@16.8.2/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.2/umd/
• scheduler: https://unpkg.com/scheduler@0.13.2/umd/

16.8.1 (February 6, 2019)

React DOM and React Test Renderer

• Fix a crash when used together with an older version of React. (@bvaughn in #14770)

React Test Utils

• Fix a crash in Node environment. (@threepointone in #14768)

Artifacts

• react: https://unpkg.com/react@16.8.1/umd/
• react-art: https://unpkg.com/react-art@16.8.1/umd/
• react-dom: https://unpkg.com/react-dom@16.8.1/umd/
• react-is: https://unpkg.com/react-is@16.8.1/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.1/umd/
• scheduler: https://unpkg.com/scheduler@0.13.1/umd/

React

• Add Hooks — a way to use state and other React features without writing a class. (@acdlite et al. in #13968)
• Improve the useReducer Hook lazy initialization API. (@acdlite in #14723)

React DOM

• Bail out of rendering on identical values for useState and useReducer Hooks. (@acdlite in #14569)
• Use Object.is algorithm for comparing useState and useReducer values. (@Jessidhia in #14752)
• Don’t compare the first argument passed to useEffect/useMemo/useCallback Hooks. (@acdlite in #14594)
• Support synchronous thenables passed to React.lazy(). (@gaearon in #14626)
• Render components with Hooks twice in Strict Mode (DEV-only) to match class behavior. (@gaearon in #14654)
• Warn about mismatching Hook order in development. (@threepointone in #14585 and @acdlite in #14591)
• Effect clean-up functions must return either undefined or a function. All other values, including null, are not allowed. @acdlite in #14119

React Test Renderer and Test Utils

• Support Hooks in the shallow renderer. (@trueadm in #14567)
• Fix wrong state in shouldComponentUpdate in the presence of getDerivedStateFromProps for Shallow Renderer. (@chenesan in #14613)
• Add ReactTestRenderer.act() and ReactTestUtils.act() for batching updates so that tests more closely match real behavior. (@threepointone in #14744)

ESLint Plugin: React Hooks

• Initial release. (@calebmer in #13968)
• Fix reporting after encountering a loop. (@calebmer and @Yurickh in #14661)
• Don't consider throwing to be a rule violation. (@sophiebits in #14040)

Artifacts

• react: https://unpkg.com/react@16.8.0/umd/
• react-art: https://unpkg.com/react-art@16.8.0/umd/
• react-dom: https://unpkg.com/react-dom@16.8.0/umd/
• react-is: https://unpkg.com/react-is@16.8.0/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.8.0/umd/
• scheduler: https://unpkg.com/scheduler@0.13.0/umd/

React DOM

• Fix performance of React.lazy for large numbers of lazily-loaded components. (@acdlite in #14429)
• Clear fields on unmount to avoid memory leaks. (@trueadm in #14276)
• Fix bug with SSR and context when mixing react-dom/server@16.6 and react@<16.6. (@gaearon in #14291)
• Fix a performance regression in profiling mode. (@bvaughn in #14383)

Scheduler (Experimental)

• Post to MessageChannel instead of window. (@acdlite in #14234)
• Reduce serialization overhead. (@developit in #14249)
• Fix fallback to setTimeout in testing environments. (@bvaughn in #14358)
• Add methods for debugging. (@mrkev in #14053)

Artifacts

• react: https://unpkg.com/react@16.7.0/umd/
• react-art: https://unpkg.com/react-art@16.7.0/umd/
• react-dom: https://unpkg.com/react-dom@16.7.0/umd/
• react-is: https://unpkg.com/react-is@16.7.0/umd/
• react-test-renderer: https://unpkg.com/react-test-renderer@16.7.0/umd/
• scheduler: https://unpkg.com/scheduler@0.12.0/umd/

16.6.3 (November 12, 2018)

React DOM

• Fix bugs in Suspense and lazy. (@acdlite in #14133, #14157, and #14164)
• Fix highlighting of React.memo updates in React DevTools. (@bvaughn in #14141)
• Fix interaction of Suspense with the React Profiler. (@bvaughn in #14065)
• Fix a false positive warning when using Suspense. (@acdlite in #14158)

React DOM Server

• Fix incorrect sharing of context state between renderToNodeStream() calls. (@sebmarkbage in #14182)
• Add a warning about incorrect usage of the context API. (@trueadm in #14033)

This release was published in a broken state and should be skipped.

16.6.1 (November 6, 2018)

React DOM

• Fallback should not remount every time a promise resolves. (@acdlite in #14083)
• Fix bug where Suspense keeps showing fallback even after everything finishes loading. (@acdlite in #14083)
• Fix a crash when Suspense finishes loading in IE11. (@sophiebits in #14126)
• Fix unresolved default props in lifecycle methods of a lazy component. (@gaearon in #14112)
• Fix bug when recovering from an error thrown during complete phase. (@gaearon in #14104)

Scheduler (Experimental)

• Switch from deadline object to shouldYield API. (@acdlite in #14025)

16.6.0 (October 23, 2018)

React

• Add React.memo() as an alternative to PureComponent for functions. (@acdlite in #13748)
• Add React.lazy() for code splitting components. (@acdlite in #13885)
• React.StrictMode now warns about legacy context API. (@bvaughn in #13760)
• React.StrictMode now warns about findDOMNode. (@sebmarkbage in #13841)
• Rename unstable_AsyncMode to unstable_ConcurrentMode. (@trueadm in #13732)
• Rename unstable_Placeholder to Suspense, and delayMs to maxDuration. (@gaearon in #13799 and @sebmarkbage in #13922)

React DOM

• Add contextType as a more ergonomic way to subscribe to context from a class. (@bvaughn in #13728)
• Add getDerivedStateFromError lifecycle method for catching errors in a future asynchronous server-side renderer. (@bvaughn in #13746)
• Warn when <Context> is used instead of <Context.Consumer>. (@trueadm in #13829)
• Fix gray overlay on iOS Safari. (@philipp-spiess in #13778)
• Fix a bug caused by overwriting window.event in development. (@sergei-startsev in #13697)

React DOM Server

• Add support for React.memo(). (@alexmckenley in #13855)
• Add support for contextType. (@alexmckenley and @sebmarkbage in #13889)

Scheduler (Experimental)

• Rename the package to scheduler. (@gaearon in #13683)
• Support priority levels, continuations, and wrapped callbacks. (@acdlite in #13720 and #13842)
• Improve the fallback mechanism in non-DOM environments. (@acdlite in #13740)
• Schedule requestAnimationFrame earlier. (@acdlite in #13785)
• Fix the DOM detection to be more thorough. (@trueadm in #13731)
• Fix bugs with interaction tracing. (@bvaughn in #13590)
• Add the envify transform to the package. (@mridgway in #13766)

React DOM

• Fixed a recent <iframe> regression (@JSteunou in #13650)
• Fix updateWrapper so that <textarea>s no longer re-render when data is unchanged (@joelbarbosa in #13643)

Schedule (Experimental)

• Renaming "tracking" API to "tracing" (@bvaughn in #13641)
• Add UMD production+profiling entry points (@bvaughn in #13642)
• Refactored schedule to remove some React-isms and improve performance for when deferred updates time out (@acdlite in #13582)

16.5.1 (September 13, 2018)

React

• Improve the warning when React.forwardRef receives an unexpected number of arguments. (@andresroberto in #13636)

React DOM

• Fix a regression in unstable exports used by React Native Web. (@aweary in #13598)
• Fix a crash when component defines a method called isReactComponent. (@gaearon in #13608)
• Fix a crash in development mode in IE9 when printing a warning. (@link-alex in #13620)
• Provide a better error message when running react-dom/profiling with schedule/tracking. (@bvaughn in #13605)
• If a ForwardRef component defines a displayName, use it in warnings. (@probablyup in #13615)

Schedule (Experimental)

• Add a separate profiling entry point at schedule/tracking-profiling. (@bvaughn in #13605)

16.5.0 (September 5, 2018)

React

• Add a warning if React.forwardRef render function doesn't take exactly two arguments (@bvaughn in #13168)
• Improve the error message when passing an element to createElement by mistake (@DCtheTall in #13131)
• Don't call profiler onRender until after mutations (@bvaughn in #13572)

React DOM

• Add support for React DevTools Profiler (@bvaughn in #13058)
• Add react-dom/profiling entry point alias for profiling in production (@bvaughn in #13570)
• Add onAuxClick event for browsers that support it (@jquense in #11571)
• Add movementX and movementY fields to mouse events (@jasonwilliams in #9018)
• Add tangentialPressure and twist fields to pointer events (@motiz88 in #13374)
• Minimally support iframes (nested browsing contexts) in selection event handling (@acusti in #12037)
• Support passing booleans to the focusable SVG attribute (@gaearon in #13339)
• Ignore <noscript> on the client when when hydrating (@Ephem in #13537)
• Fix gridArea to be treated as a unitless CSS property (@mgol in #13550)
• Fix incorrect data in compositionend event when typing Korean on IE11 (@crux153 in #12563)
• Fix a crash when using dynamic children in the <option> tag (@Slowyn in #13261, @gaearon in #13465)
• Fix the checked attribute not getting initially set on the input (@dilidili in #13114)
• Fix hydration of dangerouslySetInnerHTML when __html is not a string (@gaearon in #13353)
• Fix a warning about missing controlled onChange to fire on falsy values too (@nicolevy in #12628)
• Fix submit and reset buttons getting an empty label (@ellsclytn in #12780)
• Fix the onSelect event not being triggered after drag and drop (@gaearon in #13422)
• Fix the onClick event not working inside a portal on iOS (@aweary in #11927)
• Fix a performance issue when thousands of roots are re-rendered (@gaearon in #13335)
• Fix a performance regression that also caused onChange to not fire in some cases (@gaearon in #13423)
• Handle errors in more edge cases gracefully (@gaearon in #13237 and @acdlite in #13269)
• Don't use proxies for synthetic events in development (@gaearon in #12171)
• Warn when "false" or "true" is the value of a boolean DOM prop (@motiz88 in #13372)
• Warn when this.state is initialized to props (@veekas in #11658)
• Don't compare style on hydration in IE due to noisy false positives (@mgol in #13534)
• Include StrictMode in the component stack (@gaearon in #13240)
• Don't overwrite window.event in IE (@ConradIrwin in #11696)
• Improve component stack for the folder/index.js naming convention (@gaearon in #12059)
• Improve a warning when using getDerivedStateFromProps without initialized state (@flxwu in #13317)
• Improve a warning about invalid textarea usage (@raunofreiberg in #13361)
• Treat invalid Symbol and function values more consistently (@raunofreiberg in #13362 and #13389)
• Allow Electron <webview> tag without warnings (@philipp-spiess in #13301)
• Don't show the uncaught error addendum if e.preventDefault() was called (@gaearon in #13384)
• Warn about rendering Generators (@gaearon in #13312)
• Remove irrelevant suggestion of a legacy method from a warning (@zx6658 in #13169)
• Remove unstable_deferredUpdates in favor of unstable_scheduleWork from schedule (@gaearon in #13488)
• Fix unstable asynchronous mode from doing unnecessary work when an update takes too long (@acdlite in #13503)

React DOM Server

• Fix crash with nullish children when using dangerouslySetInnerHtml in a selected <option> (@mridgway in #13078)
• Fix crash when setTimeout is missing (@dustinsoftware in #13088)

React Test Renderer and Test Utils

• Fix this in a functional component for shallow renderer to be undefined (@koba04 in #13144)
• Deprecate a Jest-specific ReactTestUtils.mockComponent() helper (@bvaughn in #13193)
• Warn about ReactDOM.createPortal usage within the test renderer (@bvaughn in #12895)
• Improve a confusing error message (@gaearon in #13351)

React ART

• Add support for DevTools (@yunchancho in #13173)

Schedule (Experimental)

• New package for cooperatively scheduling work in a browser environment. It's used by React internally, but its public API is not finalized yet. (@flarnie in #12624)

16.4.2 (August 1, 2018)

React DOM Server

• Fix a potential XSS vulnerability when the attacker controls an attribute name (CVE-2018-6341). This fix is available in the latest react-dom@16.4.2, as well as in previous affected minor versions: react-dom@16.0.1, react-dom@16.1.2, react-dom@16.2.1, and react-dom@16.3.3. (@gaearon in #13302)

• Fix a crash in the server renderer when an attribute is called hasOwnProperty. This fix is only available in react-dom@16.4.2. (@gaearon in #13303)

16.4.1 (June 13, 2018)

React

• You can now assign propTypes to components returned by React.ForwardRef. (@bvaughn in #12911)

React DOM

• Fix a crash when the input type changes from some other types to text. (@spirosikmd in #12135)
• Fix a crash in IE11 when restoring focus to an SVG element. (@ThaddeusJiang in #12996)
• Fix a range input not updating in some cases. (@Illu in #12939)
• Fix input validation triggering unnecessarily in Firefox. (@nhunzaker in #12925)
• Fix an incorrect event.target value for the onChange event in IE9. (@nhunzaker in #12976)
• Fix a false positive error when returning an empty <React.Fragment /> from a component. (@philipp-spiess in #12966)

React DOM Server

• Fix an incorrect value being provided by new context API. (@ericsoderberghp in #12985, @gaearon in #13019)

React Test Renderer

• Allow multiple root children in test renderer traversal API. (@gaearon in #13017)
• Fix getDerivedStateFromProps() in the shallow renderer to not discard the pending state. (@fatfisz in #13030)

React

• Add a new experimental React.unstable_Profiler component for measuring performance. (@bvaughn in #12745)

React DOM

• Add support for the Pointer Events specification. (@philipp-spiess in #12507)
• Properly call getDerivedStateFromProps() regardless of the reason for re-rendering. (@acdlite in #12600 and #12802)
• Fix a bug that prevented context propagation in some cases. (@gaearon in #12708)
• Fix re-rendering of components using forwardRef() on a deeper setState(). (@gaearon in #12690)
• Fix some attributes incorrectly getting removed from custom element nodes. (@airamrguez in #12702)
• Fix context providers to not bail out on children if there's a legacy context provider above. (@gaearon in #12586)
• Add the ability to specify propTypes on a context provider component. (@nicolevy in #12658)
• Fix a false positive warning when using react-lifecycles-compat in <StrictMode>. (@bvaughn in #12644)
• Warn when the forwardRef() render function has propTypes or defaultProps. (@bvaughn in #12644)
• Improve how forwardRef() and context consumers are displayed in the component stack. (@sophiebits in #12777)
• Change internal event names. This can break third-party packages that rely on React internals in unsupported ways. (@philipp-spiess in #12629)

React Test Renderer

• Fix the getDerivedStateFromProps() support to match the new React DOM behavior. (@koba04 in #12676)
• Fix a testInstance.parent crash when the parent is a fragment or another special node. (@gaearon in #12813)
• forwardRef() components are now discoverable by the test renderer traversal methods. (@gaearon in #12725)
• Shallow renderer now ignores setState() updaters that return null or undefined. (@koba04 in #12756)

React ART

• Fix reading context provided from the tree managed by React DOM. (@acdlite in #12779)

React Call Return (Experimental)

• This experiment was deleted because it was affecting the bundle size and the API wasn't good enough. It's likely to come back in the future in some other form. (@gaearon in #12820)

React Reconciler (Experimental)

• The new host config shape is flat and doesn't use nested objects. (@gaearon in #12792)

React DOM Server

• Fix a potential XSS vulnerability when the attacker controls an attribute name (CVE-2018-6341). This fix is available in the latest react-dom@16.4.2, as well as in previous affected minor versions: react-dom@16.0.1, react-dom@16.1.2, react-dom@16.2.1, and react-dom@16.3.3. (@gaearon in #13302)