🎬 SuspenseList Updates
The new <SuspenseList /> component to coordinate the loading sequence of nested suspense boundaries now comes with:
• A tail="collapsed" option.
• A warning, when single items are used.
• And various other optimizations.

⏳ Scheduler: Allow Inferring Priority from Stack
To help finding out at what priority level specific tasks are enqueued, the call stack now wraps every priority inside an additional function call.

https://github.com/facebook/react/pull/16105

🧪 Allow Nested act()s from Different Renderers
Multiple renders can now operate inside a single act() scope. This allows for e.g. using ReactDOM.render inside another component tree.

https://github.com/facebook/react/pull/16039

🎇 React Flare Updates
• Capture Phase Flare events were removed.
• Support for currentTarget was added and later changed to responderTarget.
• Press events now include a button type.
• The Scroll responder now has more functionality.

🧯 Remove React Fire Fork
The unused React Fire fork was removed. Instead, the team is focusing on React Flare. Check out Dan’s reply to the React Fire announcement for more information.

https://github.com/facebook/react/pull/16046

👚 Fabric: Add dispatchCommand
The Fabric React Native renderer now has a dispatchCommand export.

https://github.com/facebook/react/pull/16085

⚠️ Change Warning for Unacted Effects
A warning is now only issued for unacted effects inside strict and non-sync modes.

https://github.com/facebook/react/pull/16041

How using component-based design helps us build faster

This post breaks down how using a component-based design (which includes React) has helped Twitter build across all platforms.

How I ruined my application performances by using React context instead of Redux

Georges used React contexts instead of Redux for centralized states. Without a selector system, his components where getting lots of data as props, some of them were often changing and not necessary to build the view. This post is how he fixed it.

Concurrent Mode explained

Is Concurrent Mode just a workaround for “virtual DOM diffing” overhead? In this Twitter thread, Dan breaks it down.

Authenticated Routing with React, React Router, Redux & TypeScript

In this post, Fred shares how they went about authentication at Octopus Wealth utilising react-router-dom, react-redux & TypeScript.

Build your own React

How does React really work? In this talk, you'll find out. You'll write a simplified version of React from scratch, based on the real source code, including: jsx, fibers, reconciliation, hooks, and more.

A Deep Dive into React-Redux

Redux and React are frequently used together, and many people are familiar with the "Provider" and "connect" APIs from React-Redux. But how does React-Redux work, and why do we even need it in the first place? Join Redux maintainer Mark Erikson on a journey through the history and internals of React-Redux.

📌 useSubnoscription Hook

Similar to the createSubnoscription helper, the React team now maintains a useSubnoscription hook.

https://github.com/facebook/react/pull/15022

🎇 React Flare Updates

• 🔥 Redesign Core Event System
• Keyboard Responder
• Input Responder
• FocusWithin Responder

🎬 SuspenseList: tail="hidden"

A new tail="hidden" option was added to SuspenseList that hides all rows in the tail.

https://github.com/facebook/react/pull/16024

🛠 DevTools: Automatic Component Stacks

The upcoming DevTools v4 release will add an option to append a component stack when warnings or errors are logged.

https://twitter.com/brian_d_vaughn/status/1151552058731847680

🦄 Unify Deprecated/Unsafe Lifecycle Warnings

This PR reworks some of the messages behind the deprecated or unsafe lifecycle warnings.

https://github.com/facebook/react/pull/16103

🌀 Add suspenseCallback for Runtime Tracing of Loading States

When the new feature flag is enabled, the suspenseCallback property on a suspense boundary will be called during the commit phase.

https://github.com/facebook/react/pull/16134

🌍 React Docs Localizations

The Arabic localization is now online.

https://ar.reactjs.org/

⚠️ Warn When Using DefaultProps on Function Component

This change adds a warning when using defaultProps on a function component as part of the createElement changes.

https://github.com/facebook/react/pull/16210