Installs and configuration for Jest + React Testing Library

For React + Vite projects

1. Necessary installs:

yarn add --dev jest babel-jest @babel/preset-env @babel/preset-react 
yarn add --dev @testing-library/react @types/jest jest-environment-jsdom

2. Optional: If we use Fetch API in the project:

yarn add --dev whatwg-fetch

3. Update package.json scripts

"scripts: {
  ...
  "test": "jest --watchAll"

4. Create babel configuration file babel.config.js. Warning!: if you get a module type error, rename file to extension .cjs

module.exports = {
    presets: [
        [ '@babel/preset-env', { targets: { esmodules: true } } ],
        [ '@babel/preset-react', { runtime: 'automatic' } ],
    ],
};

5. Optional, but eventually necessary, create Jest config and setup:

jest.config.js

module.exports = {
    testEnvironment: 'jest-environment-jsdom',
    setupFiles: ['./jest.setup.js']
}

jest.setup.js

// In case you need to implement the FetchAPI
import 'whatwg-fetch'; // <-- yarn add whatwg-fetch