☕️ React as a UI Runtime

In this comprehensive article, Dan (@gaearon) wrote a lot about the internals of React. I highly recommend this read: https://overreacted.io/react-as-a-ui-runtime/

🏞 Partial Hydration

The partial hydration PR has now landed in master. This new mode can start hydrating a server rendered result while some parts are still loading. The goal is decrease the time to interactive.

https://github.com/facebook/react/pull/14717

📚 Component Stack in act() Warning

The warning about missing act() wrapping in some test environments now contains a component stack trace.

https://github.com/facebook/react/pull/14855

🖥 Fix SSR Context Leaks When Render Stream Destroyed Early

This PR fixes a Context memory leak in the SSR if a stream is destroyed before the render completes.

https://github.com/facebook/react/pull/14706

📡 Properly Support crossOrigin for SVG Images

We now properly case the crossOrigin property that’s used for SVG image elements.

https://github.com/facebook/react/pull/14832

👀 Fix useImperativeHandle Without Dependencies

The useImperativeHandle hook now properly behaves like no dependencies were set when the second argument is omitted.

https://github.com/facebook/react/pull/14801

📌 React v16.8.2 Patch Release

This release brings bug fixes and stability improvements around hooks and other features.

https://github.com/facebook/react/blob/master/CHANGELOG.md#1682-february-14-2019

📌 Add eslint-plugin-react-hooks/exhaustive-deps

The ESLint plugin for React hooks now has a new exhaustive-deps rule that verifies that the proper dependency array is specified. It also warns when assigning a to variable from an outside closure.

https://github.com/facebook/react/pull/14636

🤹‍♀️ act() Examples

Sunil (threepointone) created notes that explains the necessity of the new act() API for writing tests that should resemble production behavior.

https://github.com/threepointone/react-act-examples

🗺 RFC: createElement Changes

A new RFC outlines changes to React.createElement() that simplifies the object representation and will also allow forwardRef to be removed in the future.

https://github.com/reactjs/rfcs/pull/107

🌍 New React Internationalization Repo: Greek

The list of internationalization repos is still growing. This week, we’re adding the Greek repository.

https://github.com/reactjs/el.reactjs.org

🕳 Deal with Fallback Content in Partial Hydration

This PR allows a dehydrated suspense boundary to be in three possible states (as encoded with different comment nodes).

https://github.com/facebook/react/pull/14884

🐞 Fix UMD Builds by Re-exporting the Scheduler Priorities

A recent regression caused the v16.8.2 release to break input elements when using the UMD build. This was fixed by properly exporting the Scheduler priorities.

https://github.com/facebook/react/pull/14914

📌 React v16.8.3 Patch Release

This release fixes several bugs around React DOM.

https://github.com/facebook/react/releases/tag/v16.8.3

🌏 Is React Translated Yet? ¡Sí! Sim! はい！

A new blog post explains the React documentation internationalization effort and mentions the first three live websites: Spanish, Japanese, and Brazilian Portuguese.

https://reactjs.org/blog/2019/02/23/is-react-translated-yet.html

💼 RFC: Focus Management API

Devon Govett (devongovett) worked on an RFC for a new API to improve focus handling in React. Feedback welcome!

https://github.com/reactjs/rfcs/pull/109

⏱ Add New Mock Build of Scheduler

To control the Scheduler queue in test environments, a new mock version of the Scheduler was added.

https://github.com/facebook/react/pull/14964

🌎 React Docs Language Switcher

With the release of the first three localizations (see above), the documentations now also feature a language switcher

https://reactjs.org/languages

🛠 DevTools: Support Editable useState Hooks

To allow a future DevTools version to edit useState hooks, a new overrideHookState was added to work with react-debug-tools.

https://github.com/facebook/react/pull/14906

🌍 6 New React Internationalization Repos

With six new internationalization repos added last week, we’re now at a total of 38. This week brings:
- Gujarati: reactjs/gu.reactjs.org
- Central Khmer: reactjs/km.reactjs.org
- Kurdish: reactjs/ku.reactjs.org
- Lithuanian: reactjs/lt.reactjs.org
- Telugu: reactjs/te.reactjs.org
- Urdu: reactjs/ur.reactjs.org

⏳ Scheduler: Pass didTimeout to Callbacks

To avoid unnecessary checks to shouldYield, Scheduler callbacks now receive a didTimeout argument.

https://github.com/facebook/react/pull/14931