jest-extended

What is jest-extended?

jest-extended is a set of additional matchers for Jest, a popular JavaScript testing framework. It extends Jest's built-in matchers with a variety of new ones, making it easier to write more expressive and comprehensive tests.

What are jest-extended's main functionalities?

Array Matchers

Checks if the value is an array.

expect([1, 2, 3]).toBeArray();

Object Matchers

Checks if the object contains the specified key.

expect({ a: 1 }).toContainKey('a');

String Matchers

Checks if the string starts with the given substring.

expect('hello world').toStartWith('hello');

Number Matchers

Checks if the number is within the specified range.

expect(10).toBeWithin(5, 15);

Date Matchers

Checks if the date is after the specified date.

expect(new Date('2023-01-01')).toBeAfter(new Date('2022-12-31'));

Other packages similar to jest-extended

chai

Chai is an assertion library for Node.js and the browser that can be delightfully paired with any JavaScript testing framework. It provides a variety of assertion styles (should, expect, assert) and is highly extensible.

should

Should.js is an expressive, readable, and powerful assertion library for Node.js and the browser. It extends Object.prototype to provide a more natural way to write assertions.

expect

Expect is a minimalistic assertion library for JavaScript. It is often used with Jest but can be used standalone. It provides a set of simple and intuitive matchers.

README

jest-extended

🃏💪

Additional Jest matchers

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Problem

Jest is an amazing test runner and has some awesome assertion APIs built in by default. However, there are times when having more specific matchers (assertions) would be far more convenient.

Solution

jest-extended aims to add additional matchers to Jest's default ones making it easy to test everything 🙌

Contributing

If you've come here to help contribute - Thanks! Take a look at the contributing docs as a way of getting started.

Installation

See the Installation Guide on Jest Extended documentation site.

Setup

See the Setup instructions on Jest Extended documentation site.

Matchers

See all available matchers and interactive repl on Jest Extended documentation site.

LICENSE

MIT

Changelog

4.0.2

Patch Changes

• 1f88101: Mark 2nd param of toHaveBeenCalledBefore and toHaveBeenCalledAfter optional