Juan Cruz Martinez
Mar 16, 2022 ⋅ 11 min read

React app testing: Jest and React Testing Library

Juan Cruz Martinez I'm an entrepreneur, developer, author, speaker, YouTuber, and doer of things.

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2 Replies to "React app testing: Jest and React Testing Library"

  1. There is a missing chunk of code on the bottom of the first code block for App.js. The code does not work as it is. If you are stuck there, use the following code.

    import ‘./App.css’;
    import { useState, useEffect } from ‘react’;
    import { formatUserName } from ‘./utils’;

    function App() {
    const [users, setUsers] = useState([]);
    // load data from server

    useEffect(()=> {
    let mounted = true;
    const getUsers = async () => {
    await fetch(‘https://jsonplaceholder.typicode.com/users’)
    .then(response => response.json())
    .then((data) => {
    if (mounted) {

    return (


    users.map( user => (
    { user.name } { formatUserName(user.username) }


    export default App;

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