Tutorials on Jest

Learn the practical techniques you need today to modify any large-scale codebase without the hassle of manual, one line at a time refactors. We use real world tools such as Facebook's jscodeshift to apply these powerful concepts on actual codebases. The course goes beyond just theory to practical…

In the previous post, we created a unit test for a function. In this post, we're going to create a unit test for a component using @testing-library/react. Since we're using Create React App the React Testing Library is already installed in our dependencies. If you don't have it, install the package…

Tests make sure that changes in code don't break its functionality. For testing an app, we need a test runner. Create React App provides us a test runner called jest. Let's create a new app and inspect what it contains. The src directory contains all the app code and a file called App.test.tsx.…

Building single-page React applications has never been easier. With a single command, Create React App (CRA) scaffolds an entire React application with development/build tools, such as Babel and Jest, automatically configured and integrated into the project. Getting started requires no additional…

When writing tests for your application, it can be tedious and distracting to switch between the terminal and IDE to execute tests and verify that all tests are passing. What if there was a more streamlined approach that simply displayed the results of tests directly within the IDE, with each…

Jest is an open-source, JavaScript testing framework maintained by Facebook. With an exceptionally large assertion library and a simple, well-documented API, writing tests for JavaScript code with Jest is easy and requires no additional configuration. For TypeScript code (and JavaScript code that…

Hooks in React are a new, popular, and extensible way to organize side-effects and statefulness in React components. By composing the base hooks provided by React, developers can build their own custom hooks for use by others. Redux, ApolloClient, and Callstack have distributed custom hooks to…