Jest

JavaScript testing framework with a focus on simplicity

Jest is a JavaScript testing framework with a focus on simplicity. It works with projects using Babel, TypeScript, Node, React, Angular, and Vue.

How to write React applications in TypeScript using TDD, highlighting features of the IDE

Make a very simple class component with local counter state, then make a type definition for that state.

Follow the React pattern of container/presentation components by refactoring the code and tests.

Use the visual debugger in the IDE for smarter TDD.

Create a React+TypeScript project with the create-react-app scaffolding tool.

Add event handling to a stateful class component by first writing tests during development.

Test-first development with Jest in the IDE.

Learn how to run a single test right from the editor.

In a test file, hover over an error to get more information about it.

Use the Structure tool window for quick navigation around large test files.

Use the Go to Symbol popup to go to a test.