React TL;DR #4 – Most Useful React Content From October 2019


8 New ES10 (ES2019) Features by Example

New features:

  • Optional Catch Binding
  • Object.fromEntries
  • Array.flat
  • Array.flatMap
  • String#{trimStart,trimEnd}
  • Dynamic Import
  • globalThis object

Introducing Concurrent Mode (Experimental)

Concurrent Mode is a set of new features (still experimental!) that help React apps stay responsive and adjust to the user’s device capabilities and network speed.


  • Suspense for Data Fetching – describes a new mechanism for fetching data in React components.
  • Concurrent UI Patterns – shows some UI patterns made possible by Concurrent Mode and Suspense.
  • Adopting Concurrent Mode – explains how you can try Concurrent Mode in your project.
  • Concurrent Mode API Reference – documents the new APIs available in experimental builds.

React Spaces

React Spaces allow you to divide a page or container into anchored, scrollable and resizable spaces.


  • No styling to achieve simple or complex layouts.
  • Spaces know how to behave in relation to each other and resize accordingly.
  • Spaces don’t have any visual element to them (even padding or margins). You can fill them with whatever you want.

React Navigation 5.0 now has:

  • A new dynamic component based API
  • Hooks first API
  • Updating options from component
  • First-class types with TypeScript
  • Redux DevTools integration

A strategy for writing good test

  • Write a test that fails (RED). This is to avoid false positives (tests passing when they shouldn’t be)
  • Write the minimum amount of code required to get the test passing (GREEN).
  • Refactor the code (REFACTOR). This might mean writing a more efficient technical solution or a more refined approach. As long as the test continues to stay green, you know there is no regression.

“Quality software is rarely developed alone, eventually other people will need to read your code.”

This is why:

  • Always give a name for numbers
  • Use clear variable names
  • Refactor with tiny, named functions
  • Add useful test descriptions

Stay updated with the newest React TL;DR. 

What is React TL;DR?

How do you decide which React news can be useful to you? Or how something matches your interest or bring any value?

Content tools are easy to fool and collect a lot of crap that doesn’t really help or improve your work and this is why we decided to select the most useful React news ourselves.

Our TL;DR version delivers the essence from the article and helps you decide if it’s worth reading further to you.

Again – we don’t use any engines or tools. It is all selected by ourselves, based on what we have learned and gained profit from. No b#$%it provided.

Say hello to React TL;DR – a human filter for most useful React content.

  • Mariusz Marcak

    Mariusz Marcak

    Posted on

    Spoko post, elo

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