➡️ Rename useImperativeMethods to useImperativeHandle

The hook to customize the instance value that is exposed to parent components when using ref is now called useImperativeHandle.

https://github.com/facebook/react/pull/14565

👀 DevTools: Better Display for String Contexts

Context values that hold a primitive data type are now properly formatted in DevTools.

https://github.com/facebook/react-devtools/pull/1256

🛠 Separate Current Owner and Dispatcher

These two private APIs give deep access to React internals and a few external libraries depend on them. If your library does, check out the pull request for a migration strategy.

https://github.com/facebook/react/pull/14548

🌀 Release 16.8.0-alpha.0

If you’ve played around with hooks before using the alpha release, make sure to upgrade to 16.8.0-alpha.0 and benefit from all bug fixes that were published with 16.7.0.

https://twitter.com/dan_abramov/status/1083139151720001543

🛑 Allow useReducer to Bail Out

Bailing out from state changes was a long requested feature for hooks. With a recent change, returning the same state from a useReducer call will now avoid re-rendering the component.

https://github.com/facebook/react/pull/14569

🎉 React DevTools 3.6

A new version of the React DevTools browser plugin is out adding support for hooks and a lot more.

https://chrome.google.com/webstore/detail/react-developer-tools/fmkadmapgofadopljbjfkapdkoienihi

📌 Labels for Custom Hooks

Together with the new hook support in the DevTools, useDebugValue allows to configure labels for custom hooks. Make sure to check out the docs entry.

https://github.com/facebook/react/pull/14559

🐞 Support Hooks in Shallow Renderer

If you’re using React’s shallow renderer for testing your components, you can now continue to do so even when working with hooks.

https://github.com/facebook/react/pull/14567

🛠 DevTools: $r for Function Components

When selecting a React element in DevTools and typing $r in the console, you can access the selected component instance. For function components, this will now return a useful fallback.

https://github.com/facebook/react-devtools/pull/1281

📝 Creating Expensive Objects

The documentation now contains a new section on how to create expensive objects. The useMemo paragraph was also updated to make it clear that you can not rely on it being called exactly once.

https://reactjs.org/docs/hooks-faq.html#how-to-create-expensive-objects-lazily

🌀 Release 16.8.0-alpha.1

A new alpha with hooks support is out including the new useDebugValue API and a lot of other fixes. Make sure to update if you’re on the pre-release build.

https://twitter.com/dan_abramov/status/1083139151720001543

👀 Add ESLint Rule Playground

Working on linter rules can be frustrating as editors want to avoid reloading it. This new playground rule acts as a proxy to your in-development rule and will reload it on every recheck.

https://github.com/facebook/react/pull/14609

⚠️ Error When Using Hooks Inside Hooks

React now properly warns you when you use hooks inside some other hooks.

https://github.com/facebook/react/pull/14608

📌 Enable Hooks

Hooks are now turned on by default and will be part of the next release 🎉. The release is also very close.
https://github.com/facebook/react/pull/14679

🏫 Warn When Hooks Type Change

React will now warn when you are returning different hooks on subsequent re-renders. Don’t forget the first Rule of Hooks.
https://github.com/facebook/react/pull/14585

🥢 Double-render Function Component With Hooks in Strict Dev Mode

If you’re using <StrictMode> in DEV builds, function components that call hooks will now be called twice to make it easier to spot side effects.
https://github.com/facebook/react/pull/14654

🔄 Support Sync Thenables for lazy()

You can now pass a synchronous thenable (an object where the then property callback is executed synchronously) into lazy().
https://github.com/facebook/react/pull/14626

✌️ Warn When Passing Second Callback to setState/dispatch in Hooks

In class components, you can pass in a second callback to this.setState() that is run when the update is applied. When using hooks, this is not supported.
https://github.com/facebook/react/pull/14625

🛑 Disallow Reading Context During useMemo, etc.

The callback functions of useMemo, use(Layout)Effect, useReducer, and useState can no longer read context by accessing the internal dispatcher.
https://github.com/facebook/react/pull/14653