Category: Jest - Page 2

Jest is an open-source testing framework built on JavaScript, designed to work with React web applications. It is one of the more popular test runners, and the default choice for React projects. The below articles help solve issues that I ran in to when working with Jest on a number of projects for clients. For more information on Jest itself, take a look at the Jest website. In addition to the Jest category, you may find the Testing category helpful.

Unit testing localizations for React app

Unit Testing Localizations in React App. Solution for Mocking Intl API

Last Updated: 29 September 2022

Solution for error 'RangeError: timeZone is not supported.' when unit testing Intl API. Caused by Node not supporting time zones

Small dog doing React component unit testing

Check React Component Props are Passed to Child in Jest Unit Test

Last Updated: 21 November 2022

How to unit test a React parent component logic, and check that a child component is passed the correct props. Test if a component is called with expected argument using React Testing Library.

Calendar showing one date highlighted for Jest mock article

How to Mock the Date in Jest Consistently

Last Updated: 21 November 2022

Struggling to mock the Date in Jest using CRA? Need consistant global Date testing for React? This article provides the solution.

React Jest Tests Failing Using Lottie.js Solved

Last Updated: 29 September 2022

TypeError: Cannot set property 'fillStyle' of null when using lottie-react in Jest testing solved.