This Week In React #105: useEvent, Next.js Layouts, Remix, Storybook, Reanimated 3, Expo 45, Tamagui, TypeScript, Markdoc...

May 24, 2022

React

React useEvent() RFC

Dan Abramov's RFC suggests to add a new useEvent(fn) hook in React core, without any dependency array. The unstable function/closure passed as a parameter is then stabilized (it keeps the same identity over time). This helps avoid the stale closure problem (when ESLint rules are not respected) while simplifying optimization via React.memo(), and avoiding useEffects from re-executing. Changes planned to ESLint rules: the stabilized function does not need to be passed into other dependency arrays, and an "onEvent" / "handleEvent" convention could be adopted.

I gave my positive feedback in the pull-request (lots of comments there, especially on the naming of that hook). For me, it's really a missing piece in the initial hooks design, and many apps already use a workaround based on useLayoutEffect.

useEvent, the missing React hook is a great 3 minutes video to understand the big picture.

Next.js Layouts RFC

Next.js will modernize its routing infrastructure. This will help leverage React 18 features, and other upcoming features.

They plan for incremental adoption: the ./pages folder continues to work as before, and you can gradually move things to a new ./app folder, which also activates Server Components 🤯.

There will be support for nested routes/layouts based on a layout.js naming convention. Requests will be executed in parallel (without waterfall). This article is only the 1st part of a huge RFC: the 2nd part is coming.

Extras:

📜 Building a Design System from scratch: Maxime sharing all the details behind his personal React design system , based on Stitches
📜 Building a Mini Next.js: Jonas shows how to replicate Next.js file-system routing and SSR with getServerSideProps, using Vite and Fastify.
📜 Remix and “The Edge”: Jim recently joined the Remix team. This explains how Remix leverages the Edge (ie Deno and Cloudflare Workers 😏) to be both fast and dynamic.
📜 Storybook Performance: Vite vs Webpack: Storybook has pluggable builders, so which one to use? This benchmark shows that Vite does not always win against Webpack, on a large IBM Carbon 250 comps Storybook
📜 What the useEvent React hook is (and isn't): opinion of a Solid contributor
📜 Getting started with Markdoc in Next.js: Stripe just open-sourced their doc tool Markdoc
📜 React key attribute: best practices for performant lists: good illustration on problems happening when you use index or random keys
📜 (P)react vs Web Components: a Xoogler's perspective
📜 Reading Source Code: React-Query
📜 You Don’t Need A UI Framework
📜 What You Need to Do to Improve Performance in Next.js
📜 How to solve React useEffect infinite loops
📜 What I learnt at Reactathon 2022
📜 Using Next.js ISR with Serverless Cloud
👥 Remix Conf: starts today!
👥 Reactathon 2022 livestreams: day 1, day 2, day 3
🧑‍🎓 Advanced-Remix: workshop open-sourced by Kent
🧑‍🎓 Complex State Management in React with Jotai and XState
🐦 TypeScript 4.8 + "as props": possible improvement?
🐦 well-named function inside useEffect
📦 eslint-plugin-react v7.30: new jsx-no-leaked-render rule very useful. Permits to avoid rendering a 0 with {count && <div>{count}</div>} (which makes React-Native crash 😅)
📦 Remix 1.5: officiel Deno support
📦 Reagraph: WebGL Graph Visualizations
📦 Playright 1.22: possible to test React components

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React-Native

Announcing Reanimated 3

New version in RC. Supports the new Fabric architecture, but also the old one to help gradual adoption. Reanimated v2 code continues to work on v3, but the old Reanimated v1 API is removed. Bonus: demo Reanimated 3 + RNGH + Screens

Microsoft - React Native Developer Tools

Adam announces the launch of the React Native Developer Tools community project. This is a repo (rnx-kit) with many useful tools for a React-Native project related to Metro, TypeScript, Jest... Microsoft already uses it on various products like Office, Xbox, and Teams.