npm install --save-dev jest

Add the following section to your package.json, then run npm test:

{
  "scripts": {
    "test": "jest",
  }
}

By default, the current version of Jest will not recognize ES6 import statements. In order for you to be able to use ES6 modules for this project you may install the following required dependencies:

npm install --save-dev babel-jest @babel/core @babel/preset-env

Configure Babel to target your current version of Node by creating a babel.config.js file in the root of your project:

module.exports = {
  presets: [['@babel/preset-env', {targets: {node: 'current'}}]],
};

npm install --save-dev @babel/preset-typescript

Add @babel/preset-typescript to the list of presets in your babel.config.js.

module.exports = {
  presets: [
    ['@babel/preset-env', {targets: {node: 'current'}}],
    '@babel/preset-typescript',
  ],
};

You may also want to install the @types/jest module to provide full typing when writing your tests with TypeScript.

npm install --save-dev @types/jest