React 16 Known Regressions

[gaearon]

Going to track them here since website issues are creating a lot of noise.

Fixed in Master

• UMD Production builds define global variables #10909 Extra variable in UMDs, fixed in Don't let UMD create extraneous global variables #10935
• Warning: Stateless function components cannot be given refs. Attempts to access this ref will fail.null after updating to React 16 #10831 null instead of component stack in a warning, fixed in Fix "null" instead of the component stack in a warning #10915
• The IE11 document.implementation.createHTMLDocument API requires the title argument to be specified #10865 Crash when hydrating on IE11 in development, fixed in Fix for createHTMLDocument API specific to IE11 #10921
• <svg tabIndex="2"> doesn't work  #10987 tabIndex getting lost on SVG, fixed in Fix tabIndex attribute for SVG #11033
• Fiber cannot render to DocumentFragment/ShadowRoot #11017 Crash rendering into shadow root, fixed in Fix rendering into shadow root #11037
• Production Check in react-test-renderer #10938 We should allow running test and shallow renderers in production again, fixed in Add production bundles for Test and Shallow renderers #11112.
• Returning plain string from component renders collapsed text nodes on server #10598 SSR doesn't separate unrelated text nodes in some cases, fixed in Adjacent text nodes in SSR should have comments between them despite components #11109.
• SSR: ReactDOM client and server handling newlines differently causing mismatch warnings #11103 SSR: ReactDOM client and server handling newlines differently causing mismatch warnings, fixed in Ignore CR/LF differences when warning about markup mismatch #11119.
• Bump peer deps of react to ^16.0.0 #11156 Peer dependencies warn for beta?
• In React 16, onMouseEnter is triggered an extra time when entering a new child #10906 onMouseEnter fires twice after a child is added, fixed in Fix incorrect calculation of onMouseEnter/Leave component path #11164.
• onMouseEnter triggered on children in React 16 #11152 onMouseEnter fires when hovered over a child, fixed in Fix incorrect calculation of onMouseEnter/Leave component path #11164.
• Shallow renderer: subsequent setState calls inside componentWillMount discard the previous ones #11161 Shallow renderer doesn’t merge multiple setState() calls in componentWillMount correctly, fixed in Shallow renderer: support multiple setState invocation #11167.
• SSR throws an obscure error on bad style prop, fixed in Fix obscure error message when passing an invalid style value for SSR #11173.
• React 16 does not render text area placeholder initially in IE11 Win10 #11172 IE11 loses textarea placeholder on first render, fixed in Don't set empty placeholder to work around IE11 bug #11177.
• Unexpected SSR difference warning with SVG <filter> primitives #10772 False positive warning when rehydrating camel-case SVG tag names, fixed in Fix false positive SVG hydration warning for mixed case tags #11174.
• React 16 fails to rehydrate noscripts #10993 False positive warning when rehydrating <noscript>, fixed in Fix false positive <noscript> rehydration text difference warning in React 16 #11157.
• autoFocus doesn't work with SSR in React 16 #11159 autoFocus doesn't work with SSR.

New Features Added in Master

• Allow on attribute (but not other on... attributes). Allow custom attribute named on to be passed on to elements #11153
• Allow explicitly shallow ignore of hydration warning. Ignore SSR warning using explicit suppressHydrationWarning option #11126

[ptomasroos]

Would it be possible to get a updated next on npm for the react 16 regressions that been fixed?

[iamdustan]

@ptomasroos 16.1 will be releaed in the not-too-distant future.

[blling]

Maybe this issue should keep open until 16.1 released ?

[ptomasroos]

Thanks for the feedback @iamdustan

[gaearon]

We’ll release it within a week or two. The work on these problems is done so there’s no need to keep the issue open. I’ll lock because comments here won’t help get the release out faster. We need to test it more at Facebook first.

[gaearon]

React 16.1.0-beta has been released. Please update react, react-dom, and react-test-renderer (if you use it) to this version and let us know if it solved the issue! We’d appreciate if you could test before Monday when we plan to get 16.1.0 out.