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 #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/