Chai is a popular assertion library for Node.js and browsers that provides a clean and expressive syntax for writing test assertions. It offers a wide range of assertion styles, including should, expect, and assert, allowing developers to choose the one that best fits their testing preferences. Chai integrates seamlessly with popular testing frameworks like Mocha and Jasmine, making it a versatile choice for writing clear and readable test cases.
Alternatives:
jest-+
mocha-+
jasmine-+
ava-+
tape-+
qunit-+
jest-expect-+
assert-+
should.js-+
expect.js-+
Tags: node.jsbrowsertestingassertionMochaJasmine
jest
v29.7.0(8 months ago)
Jest is a delightful JavaScript testing framework with a focus on simplicity and ease of use. It is widely used for testing JavaScript code, including React applications, Node.js projects, and more. Jest provides a zero-configuration setup, making it easy to get started with testing right away. It offers features like snapshot testing, mocking, code coverage, and parallel test execution.
Alternatives:
mocha-+
chai-+
jasmine-+
ava-+
tape-+
cypress-+
playwright-test-+
vitest-+
qunit-+
karma-+
Tags: javascripttestingframeworkjestmocking
Fight!
Popularity
Both Chai and Jest are widely used testing libraries in the JavaScript ecosystem. However, Jest has gained significant popularity in recent years and is currently more widely adopted than Chai.
Community Support
Jest is maintained by Facebook and has a large community of contributors, which translates to regular updates, bug fixes, and new features. Chai, on the other hand, also has an active community but is not backed by a specific organization.
Test Runners
Jest is a comprehensive testing framework that includes features like test runners, assertion libraries, and mocking capabilities, making it a complete solution out of the box. Chai, on the other hand, serves as an assertion library and can be used with different testing frameworks or test runners like Mocha or Jasmine.
Syntax and API
Chai offers different assertion styles such as should, expect, or assert, allowing developers to choose their preferred syntax. Jest, on the other hand, has its own built-in expect assertion API but also supports custom matchers. The syntax and API of Chai and Jest are both expressive and easy to understand.
Setup and Configuration
Jest has a zero-configuration setup, which means you can start writing tests immediately without any additional configuration. Chai, on the other hand, requires some setup to integrate with a testing framework or test runner. While Jest offers a smooth onboarding experience, Chai provides more flexibility when it comes to customization.
Mocks and Spies
Jest includes built-in mocking and spying capabilities, allowing you to easily mock dependencies and spy on function calls. Chai, on the other hand, does not provide native mocking and spying features and requires additional libraries like Sinon.js for those functionalities.
