What is @types/jest?
The @types/jest package provides TypeScript type definitions for Jest, a popular JavaScript testing framework. This allows developers to use Jest in TypeScript projects with type checking and IntelliSense support for Jest's API.
What are @types/jest's main functionalities?
Type Definitions for Jest Functions
Provides type definitions for Jest's global functions like 'test' and 'expect', enabling type checking and autocompletion in TypeScript.
test('adds 1 + 2 to equal 3', () => {
expect(1 + 2).toBe(3);
});
Type Definitions for Matchers
Includes type definitions for Jest's matchers, such as 'toMatch', 'toBe', and 'toHaveProperty', ensuring correct usage with TypeScript.
expect('hello').toMatch(/hello/);
Type Definitions for Mock Functions
Provides type definitions for Jest's mock functions and their methods like 'mockReturnValue' and 'mockImplementation'.
const mockFunction = jest.fn();
mockFunction.mockReturnValue('default value');
Type Definitions for Jest Configuration
Offers type definitions for Jest configuration options, which can be used when setting up Jest in a TypeScript project.
const jestConfig = {
verbose: true,
collectCoverage: true
};
Other packages similar to @types/jest
@types/mocha
Provides TypeScript type definitions for Mocha, another testing framework. Similar to @types/jest, it allows developers to use Mocha with TypeScript's type checking.
@types/chai
Offers type definitions for Chai, an assertion library that can be used with testing frameworks like Mocha. It serves a similar purpose to @types/jest but for Chai's API.
@types/sinon
Contains TypeScript type definitions for Sinon, a library for spies, stubs, and mocks in JavaScript tests. It is similar to the mock functionality provided by Jest and its type definitions in @types/jest.
Installation
npm install --save @types/jest
Summary
This package contains type definitions for jest (https://jestjs.io/).
Details
Files were exported from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/jest.
Additional Details
Credits
These definitions were written by Asana (https://asana.com)
// Ivo Stratev, jwbay, Alexey Svetliakov, Alex Jover Morales, Allan Lukwago, Ika, Waseem Dahman, Jamie Mason, Douglas Duteil, Ahn, Jeff Lau, Andrew Makarov, Martin Hochel, Sebastian Sebald, Andy, Antoine Brault, Gregor Stamać, ExE Boss, Alex Bolenok, Mario Beltrán Alarcón, Tony Hallett, Jason Yu, Pawel Fajfer, Alexandre Germain, Adam Jones, and Tom Mrazauskas.