What is mocha?
Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. Mocha tests run serially, allowing for flexible and accurate reporting, while mapping uncaught exceptions to the correct test cases.
What are mocha's main functionalities?
Test Organization
Organize tests in suites and sub-suites using describe() and context(), and specify test cases using it().
"use strict";\nconst assert = require('assert');\ndescribe('Array', function() {\n describe('#indexOf()', function() {\n it('should return -1 when the value is not present', function() {\n assert.equal([1, 2, 3].indexOf(4), -1);\n });\n });\n});
Asynchronous Testing
Support for testing asynchronous code with ease, using callbacks, promises, or async/await.
"use strict";\nconst assert = require('assert');\ndescribe('User', function() {\n describe('#save()', function() {\n it('should save without error', function(done) {\n const user = new User('Luna');\n user.save(function(err) {\n if (err) done(err);\n else done();\n });\n });\n });\n});
Hooks
Lifecycle hooks such as before(), after(), beforeEach(), and afterEach() for setting up preconditions and clean-up after tests.
"use strict";\ndescribe('Connection', function() {\n before(function() {\n // runs once before the first test in this block\n });\n\n after(function() {\n // runs once after the last test in this block\n });\n\n beforeEach(function() {\n // runs before each test in this block\n });\n\n afterEach(function() {\n // runs after each test in this block\n });\n\n // test cases\n});
Other packages similar to mocha
jest
Jest is a delightful JavaScript Testing Framework with a focus on simplicity. It works out of the box for any React project and is often compared to Mocha for its comprehensive feature set including a built-in assertion library and mock functions.
jasmine
Jasmine is a behavior-driven development framework for testing JavaScript code. It does not rely on browsers, DOM, or any JavaScript framework. Thus, it's suited for websites, Node.js projects, or anywhere that JavaScript can run. It's compared to Mocha for its clean syntax and testing capabilities.
ava
AVA is a test runner for Node.js with a concise API, detailed error output, and process isolation that lets you develop with confidence. It is often compared to Mocha for its modern, concurrent testing features, but differs in its approach to running tests in parallel by default.
☕️ Simple, flexible, fun JavaScript test framework for Node.js & The Browser ☕️
![Mocha Browser Support h/t SauceLabs](https://saucelabs.com/browser-matrix/mochajs.svg)
Links
Backers
Become a backer and show your support to our open source project on our site.
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Does your company use Mocha? Ask your manager or marketing team if your company would be interested in supporting our project.
Support will allow the maintainers to dedicate more time for maintenance and new features for everyone.
Also, your company's logo will show on GitHub and on our site - who doesn't want a little extra exposure?
Here's the info.
![MochaJS Sponsor](https://opencollective.com/mochajs/tiers/sponsors/3/avatar)
Development
You might want to know that:
- Mocha is one of the most-depended-upon modules on npm (source: libraries.io), and
- Mocha is an independent open-source project, maintained exclusively by volunteers.
You might want to help:
Finally, come chat with the maintainers on Discord if you want to help with:
- Triaging issues, answering questions
- Review, merging, and closing pull requests
- Other project-maintenance-y things
License
Copyright 2011-2022 OpenJS Foundation and contributors. Licensed MIT.
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