React Async v9 and beyond

The latest version of React Async brings support for Suspense. But perhaps the greatest development is that it's now a community project with financial backing. Async Library has some very ambitious goals and is looking for more collaborators.

🎉 Introducing Concurrent Mode (Experimental)

This week, the React team released the first documentation for Concurrent Mode at the React Conf in Las Vegas. Make sure to take some time to read through everything in detail.

https://reactjs.org/docs/concurrent-mode-intro.html

🧪 React Prereleases

All React packages are now also available in a prerelease channel. These special builds will allow you to test upcoming versions of React and help the team iron out bugs in experimental features.

https://reactjs.org/blog/2019/10/22/react-release-channels.html

✨ useDeferredValue and useTransition

Two new hooks were added to help with Concurrent React. Check out the docs: useDeferredValue and useTransition.

https://github.com/facebook/react/pull/17058

🎇 React Interaction Updates

More updates on the experimental React event system:
• FocusTable tabScope Handling and tabIndex Control
• Add Tab Handling to FocusList
• Repurpose React Accessibility Modules
• Add FocusTable colSpan Support
• Modify Scope Query Mechanism
• Add onFocusWithin Event to FocusWithin Responder

⚠️ Remove IIFE Wrappers From Dev Invariant Checks

This change updates the error transform that replaces invariant() calls with an if statement to not need an IIFE wrapper anymore.

https://github.com/facebook/react/pull/16963

🖱 Fix mouseenter Handlers Firing Twice

This PR fixes an issue with mouseenter events firing twice in certain cases.

https://github.com/facebook/react/pull/16928

👉 Selective Hydration

Selective Hydration, a smarter way to hydrate SSR rendered apps, is being actively worked on:
• ReactDOM.unstable_scheduleHydration(node)
• Prioritize the Last Continuous Target
• Increase Priority for Non-synchronous Discrete Events and Retries

🧹 Upgrade to Jest 24

React is now on the latest version of Jest again!

https://github.com/facebook/react/pull/15778

🤫 Allow Suspense Mismatch on the Client to Silently Proceed

Silently try to hydrate bad mismatches instead of gracefully regenerate the content on the client.

https://github.com/facebook/react/pull/16943

🐛 DevTools: Trace Updates

This diff adds the Trace Updates feature (for DOM only so far) that can be used to highlight updated elements in the browser.

https://github.com/facebook/react/pull/16989

👋 Remove createBatch Experiment

The idea of this API was to coordinate an update to a root with its imperative container in a multiple root React app.

https://github.com/facebook/react/pull/17035

🚀 React 16.11.0

The main change of this release is that the unstable_ prefixed concurrent APIs are now removed from the stable release since they are now available on the experimental release.

https://github.com/facebook/react/releases/tag/v16.11.0

➡️ Rename createSyncRoot to createBlockingRoot

This avoids confusion with the Legacy mode.

https://github.com/facebook/react/pull/17165

Announcing Ionic React

In this post, Max Lynch (Ionic CEO) announces the general availability of Ionic React, a native React version of Ionic Framework that allows developers to build apps for iOS, Android, Desktop, and the web as a Progressive Web App. Max dives into the details of why Ionic chose to go in this direction and what it could mean for React devs going forward.

How Instagram uses Redux to Improve Performance

This is the third part in a series of blog posts by Instagram engineer Glenn Conner on steps the Instagram team took to improve the speed and performance of the app. This post specifically discusses how they use Redux to manage state on Instagram

How to Authenticate with Next.js and Auth0: A Guide for Every Deployment Model

In this article, Sandrino Di Mattia (Senior Engineering Manager at Auth0) explains how (and where) to authenticate your user in the different deployment models that exist for Next.js.

Lifting state up is killing your React app

How could it be possible that one of the 12 main concepts listed in React official documentation might lead to poor performance? This (controversial) article considers a situation when it’s indeed the case.

Building a Full-Stack App with Serverless and React

Serverless-Stack.com is a comprehensive, open source guide for building full-stack apps with Serverless and React on AWS. The new edition of the guide has been updated to use React Hooks and it also features a section on the best practices for building Serverless apps

Full-Page React Transitions

A library of 21 full-page React Router transitions

Introducing Concurrent Mode (Experimental) – Official React Blog

Just announced at React Conf, this page provides a theoretical overview of Concurrent Mode. As a general reminder, don’t rely on experimental builds of React in production apps 🙂