Testing JavaScript code is essential for ensuring the reliability and functionality of your javascript-based application. A variety of tools are available to help developers automate and streamline their testing process. Below are the top 15 tools, according to TestingBot, for JavaScript testing in 2024. We've sorted this list by popularity, with a detailed look at each of their features, pros and cons.
This list was last updated on June 13, 2024.
Top 15 List
1. Jest
Jest is a JavaScript testing framework maintained by Facebook and is particularly well-suited to test React applications. Jest offers a rich API for creating and running tests.
Jest Setup
Jest is very simple to setup, simply add it to your project yarn add --dev jest.
Next, add this to your package.json:
"scripts": {
"test": "jest"
}
You can now run the tests with yarn test or npm test:
> yarn test
yarn run v1.1.0
$ jest
PASS ./testingbot.test.js
✓ it should run a test on TestingBot (134ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 0.134s
Ran all test suites.
✨ Done in 0.134s.Jest Mocks
Jest features built-in matchers, spies and a full blown out mocking library. You can easily add mocks with jest.fn() and add own mock data in a __mocks__ directory.
ES6 Class Mocks are also supported:
-
Automatic mocks:
This lets you spy to calls on all methods, returning unfined
-
Manual mocks:
Implement your own mock behavior in a
__mocks__sub-directory - Selective mocking using
mockImplementation()ormockImplementationOnce().
Jest Reporting
Jest comes with its own coverage reporting function. This feature displays the amount of code that is covered by your (Jest) tests.
Code coverage insights are useful to determine whether your tests cover enough of your code. If the coverage is low, you might consider adding more tests to cover all your code.
> yarn test --coverage
yarn run v1.1.0
$ jest "--coverage"
PASS ./testingbot.test.js
✓ it should run a test on TestingBot (134ms)
-------------- |----------|----------|----------|----------|
File | % Stmts | % Branch | % Funcs | % Lines |
-------------- |----------|----------|----------|----------|
All files | 100 | 100 | 100 | 100 |
testingbot.js | 100 | 100 | 100 | 100 |
-------------- |----------|----------|----------|----------|
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 0.134s
Ran all test suites.
✨ Done in 0.134s.Delta Testing With Watch
Jest is able to run in watch mode. In this mode, Jest runs the appropriate tests automatically whenever you change the code. You can use the --watchAll CLI argument to monitor your application for changes while developing.
Jest Final verdict
Below are both the advantages and disadvantages of Jest compared with other testing tools.
Pros:- Easy to set up and use.
- Built-in mocking and assertion libraries.
- Snapshot testing for UI components.
- Fast parallel test execution.
- Integrates with Puppeteer and Playwright
- Can be overkill for small projects.
- Debugging can be challenging at times.
2. Mocha
Mocha is a flexible testing framework that runs on NodeJS or even in your browser. This makes it a versatile tool for unit testing and integration testing.
Mocha Setup
Mocha is easy to setup, simply add it to your project yarn add --dev mocha or npm install --save-dev mocha.
Next, add this to your package.json:
"scripts": {
"test": "mocha"
}
You can now run the tests with yarn test or npm test.
Mocha is flexible because it is modular
Mocha allows you to use various assertion libraries, mocking libraries, and other tools, making it highly adaptable to different testing needs. For example, you can mix the usage of Chai and Sinon.
const chai = require('chai');
const expect = chai.expect;
const sinon = require('sinon');
describe('Example TestingBot test', function() {
it('should be true', function() {
expect(true).to.be.true;
});
it('should call the spy', function() {
const spy = sinon.spy();
spy();
expect(spy.called).to.be.true;
});
})Mocha asynchronous testing
Mocha natively supports asynchronous testing, this allows you to test your code that involves callbacks, promises or async/await functions.
Mocha test hooks
Mocha provides hooks that run before and after tests or suites, allowing for setup and teardown operations.
For example, suppose you want to run TestingBot browser tests and want to initialize the connection to TestingBot's browser grid once, you would do this in the before hook.
before(function () {
// initialize TestingBot connection
const capabilities = {
'tb:options': {
key: process.env.TB_KEY,
secret: process.env.TB_SECRET
},
browserName: 'chrome',
browserVersion: 'latest'
}
const browser = await pw.chromium.connect({
wsEndpoint: `wss://cloud.testingbot.com/playwright?capabilities=${encodeURIComponent(JSON.stringify(capabilities))}`
})
})Mocha reporters
There are several different reporters you can use with Mocha. Popular reporters include 'spec', 'dot', and 'nyan'.
You can run a reporter by passing the --reporter flag:
mocha --reporter specMocha watcher
Mocha can watch files for changes and re-run tests automatically, making the development and debugging process faster and more efficient. You can use this feature when you are coding in your IDE and you want to make sure you do not break any tests.
mocha --watchBelow are both the advantages and disadvantages of Mocha compared with other testing tools.
Pros:- Highly extensible with numerous plugins.
- Supports both synchronous and asynchronous testing.
- Simple and clear syntax.
- Has integrations with Playwright and WebdriverIO
- Requires additional libraries for assertions and mocking.
- Steeper learning curve compared to Jest.
3. Jasmine
Jasmine is a behavior-driven development (BDD) framework for testing JavaScript code. It aims to be simple and easy to read. It does not depend on any other JavaScript framework or dependency, and runs in browsers and with NodeJS.
Jasmine Matchers
Jasmine comes with a rich set of built-in matchers that allow you to make a variety of assertions in your tests. Matchers are functions that test specific values and provide readable and clear test output. For example, see the code below were various matchers are used:
describe('Matchers Example TestingBot', function() {
it('should demonstrate the use of matchers', function() {
const result = 42; // the answer to everything ;-)
expect(result).toBe(42); // Strict equality
expect(result).not.toBe(43); // Negation
expect(result).toEqual(42); // Deep equality
expect(result).toBeLessThan(50); // Comparison
expect(result).toBeGreaterThan(30); // Comparison
});
});Jasmine Spies
Spies are functions that can replace real functions in your code to track calls and arguments. They allow you to test interactions between functions and ensure they behave as expected, without having to modify your existing code or add workarounds specifically for test cases.
describe('Spies Example', function() {
it('should track calls to a function', function() {
const obj = {
method: function() {
return 'Hello';
}
};
spyOn(obj, 'method');
obj.method();
expect(obj.method).toHaveBeenCalled();
expect(obj.method).toHaveBeenCalledTimes(1);
expect(obj.method).toHaveBeenCalledWith();
});
});Jasmine Asynchronous testing
Jasmine has built-in support for asynchronous testing which allows you to test code that relies on callbacks, promises, or async/await syntax.
describe('Asynchronous Example', function() {
it('should handle asynchronous code with done', function(done) {
setTimeout(function() {
expect(true).toBe(true);
done();
}, 1000);
});
it('should handle promises', function(done) {
Promise.resolve('Hello').then(function(result) {
expect(result).toBe('Hello');
done();
});
});
it('should handle async/await', async function() {
const result = await Promise.resolve('Hello');
expect(result).toBe('Hello');
});
});- No external dependencies are used.
- Built-in matchers for assertions.
- Supports asynchronous testing.
- Has an integration with WebdriverIO
- Limited plugin ecosystem.
- Configuration can be cumbersome for complex projects.
4. Karma
Karma is a test runner that allows you to execute JavaScript code in multiple real browsers. It works particularly well with frameworks like Jasmine and Mocha.
Real-Time Karma Testing with Multiple Browsers
Karma allows you to run tests on real browsers, providing accurate results and ensuring your application behaves correctly across different environments. Karma supports running tests in multiple browsers simultaneously. This means it's a good framework to do cross-browser testing.
To configure Karma to run tests in multiple browsers, you need to set up the karma.conf.js file:
module.exports = function(config) {
config.set({
// Base path to resolve all patterns
basePath: '',
// Frameworks to use
frameworks: ['jasmine'],
// Files to load in the browser
files: [
'src/**/*.js',
'test/**/*.spec.js'
],
// Browsers to run tests on
browsers: ['Chrome', 'Firefox', 'Safari'],
// Test results reporter to use
reporters: ['progress'],
// Continuous Integration mode
singleRun: true,
// Other configurations
// ...
});
};Continuous Integration Support
Karma integrates seamlessly with continuous integration (CI) tools such as Jenkins, Travis CI, and CircleCI. This ensures that your tests are automatically run on each code change. Using a CI with Karma improves code quality and catches issues early in the development lifecycle.
Karma Plugins
Karma is highly extensible and allows you to add plugins to enhance its functionality. You can use preprocessors, reporters and custom launchers for different browsers and environments. For example, there's a karma-testingbot-launcher which will run your tests on TestingBot's browser grid.
- Real browser testing capabilities.
- Supports continuous integration.
- Extensive configuration options.
- Works with cloud-based browser grids such as TestingBot: Karma + TestingBot.
- Setup can be complex for beginners.
- Performance can be slow with many tests.
5. Cypress
Cypress is an end-to-end testing framework built for the modern web. It provides a developer-friendly experience with a powerful API for writing and running tests.
Cypress Time Travel Debugging
Cypress offers a unique feature called "time travel", which allows you to debug your tests by seeing snapshots of your application at each step of your test. This feature helps you understand what happened during the test execution and makes it easier to identify where issues occurred.
When you run Cypress tests, the Cypress Test Runner shows each command executed with a snapshot of the application at that point. For example:
describe('My First Test', () => {
it('Visits the Kitchen Sink', () => {
cy.visit('https://example.cypress.io')
cy.contains('type').click()
cy.url().should('include', '/commands/actions')
// Capture a snapshot of the input action
cy.get('.action-email').type('test@example.com')
.should('have.value', 'test@example.com')
})
})In the Cypress Test Runner, you can click on each command to see what the application looked like at that point.
Automatic Waiting
Cypress automatically waits for elements to become visible, animations to complete and AJAX requests to finish before executing the next test command. This reduces the need for manual waits or retries, which in turn makes tests more reliable and easier to write.
Real-Time Reloads
Cypress provides real-time reloads, which means that every time you make a change to your test files, the tests will automatically re-run. This feature ensures a fast feedback loop, which makes the development and debugging process more efficient.
- Real-time reloads and debugging.
- Easy to set up and write tests.
- Great documentation and community support.
- Works with cloud-based browser grids such as TestingBot: TestingBot + Cypress integration.
- Limited browser support (only Chromium-based browsers and Firefox).
- Not suitable for unit testing.
6. QUnit
QUnit is a powerful, easy-to-use JavaScript unit testing framework developed by the jQuery team. It's suitable for both client-side and server-side testing. QUnit can run anywhere: on web browsers, NodeJS, SpiderMonkey and even in a Web Worker.
To get started, simply add QUnit to your project: npm install --save-dev qunit.
Powerful Assertions and Test Suite Management
QUnit provides a rich set of assertion methods and tools for organizing and managing test suites, which helps in creating thorough and maintainable tests.
A variety of assertion methods are available, such as assert.ok(), assert.equal(), assert.deepEqual(), and assert.throws(). This allows for detailed and specific test validations.
- Simple setup and usage.
- Supports asynchronous tests.
- Good integration with other libraries.
- Limited feature set compared to newer frameworks.
- Not as actively maintained.
7. Ava
Ava is a modern testing framework that runs tests concurrently, offering a simple syntax and powerful features for JavaScript testing.
To get started, simply add QUnit to your project: npm install --save-dev qunit.
Powerful Assertions and Test Suite Management
QUnit provides a rich set of assertion methods and tools for organizing and managing test suites, which helps in creating thorough and maintainable tests.
A variety of assertion methods are available, such as assert.ok(), assert.equal(), assert.deepEqual(), and assert.throws(). This allows for detailed and specific test validations.
- Concurrent test execution for speed.
- Clean and minimalistic syntax.
- Built-in support for ES6+ features.
- Limited plugins and integrations.
- Smaller community compared to Jest and Mocha.
8. Chai
Chai is a BDD/TDD assertion library for NodeJS and the browser. It is often used with frameworks such as Mocha.
Chai: Readable and Intuitive Syntax
Chai provides a human-readable and intuitive syntax for writing assertions, making tests easy to understand. This is achieved through its three main styles: Assert, Expect and Should.
Expect style:const { expect } = require('chai');
describe('Array', function() {
it('should start empty', function() {
const arr = [];
expect(arr).to.be.an('array').that.is.empty;
});
});const chai = require('chai');
chai.should();
describe('Array', function() {
it('should start empty', function() {
const arr = [];
arr.should.be.an('array').that.is.empty;
});
});const assert = require('chai').assert;
describe('Array', function() {
it('should start empty', function() {
const arr = [];
assert.isArray(arr, 'arr is an array');
assert.lengthOf(arr, 0, 'array has length of 0');
});
});Comprehensive Assertion Library
Chai offers a wide range of assertions for various data types and conditions. This includes deep equality checks, property checks, type checks and more. This allows thorough and detailed testing.
const { expect } = require('chai');
describe('Object', function() {
it('should have the correct properties', function() {
const obj = { a: 1, b: 2, c: { d: 3 } };
// Checking types and values
expect(obj).to.be.an('object');
expect(obj).to.have.property('a').that.is.a('number').and.equals(1);
// Deep equality
expect(obj).to.deep.equal({ a: 1, b: 2, c: { d: 3 } });
// Nested property checks
expect(obj).to.have.nested.property('c.d').that.equals(3);
});
});Plugin Support and Extensibility
Chai supports plugins that extend its functionality. This enables custom assertions and additional features, tailored to specific needs. The extensibility ensures Chai can be adapted to various testing requirements. For example, see the Chai-as-Promised Plugin for Promises example below.
const chai = require('chai');
const chaiAsPromised = require('chai-as-promised');
chai.use(chaiAsPromised);
const { expect } = chai;
describe('Async function', function() {
it('should resolve with the correct value', async function() {
const asyncFunc = () => Promise.resolve(42);
await expect(asyncFunc()).to.eventually.equal(42);
});
});- Rich and expressive assertions.
- Integrates well with other testing frameworks.
- Supports plugins for extended functionality.
- Requires a test runner.
- Can be verbose for simple tests.
9. Enzyme
Enzyme is a JavaScript testing utility for React (and React Native) that makes it easier to test the output of React Components. Below are the top three features of Enzyme.
Shallow Rendering with Enzyme
Shallow rendering is a useful feature of Enzyme that allows you to render a component one level deep. This is particularly helpful for unit testing because it isolates the component from its child components, which makes it easier to test a component in isolation.
import { shallow } from 'enzyme';
import React from 'react';
import MyComponent from './MyComponent';
describe('<MyComponent />', () => {
it('renders a <div> with the class "container"', () => {
const wrapper = shallow(<MyComponent />);
expect(wrapper.find('div.container')).toHaveLength(1);
});
});Full DOM Rendering with Enzyme Mount
Full DOM rendering is provided by Enzyme's mount function, which renders components into the DOM. This is useful for testing components that interact with DOM APIs or require the full lifecycle to be tested (for example componentDidMount).
import { mount } from 'enzyme';
import React from 'react';
import MyComponent from './MyComponent';
describe('<MyComponent />', () => {
it('calls componentDidMount', () => {
jest.spyOn(MyComponent.prototype, 'componentDidMount');
const wrapper = mount(<MyComponent />);
expect(MyComponent.prototype.componentDidMount).toHaveBeenCalled();
});
});Simulating Events
Enzyme provides a straightforward way to simulate user interactions, such as clicks and form submissions. This makes it easier to test how components respond to user input.
import { shallow } from 'enzyme';
import React from 'react';
import MyComponent from './MyComponent';
describe('<MyComponent />', () => {
it('increments counter on button click', () => {
const wrapper = shallow(<MyComponent />);
wrapper.find('button').simulate('click');
expect(wrapper.find('.counter').text()).toBe('1');
});
});- Deep integration with React.
- Provides shallow rendering for isolated tests.
- Extensive API for component testing.
- Specific to React only, not useful for other Javascript frameworks.
- Can be complex to set up with newer React features.
10. Puppeteer
Puppeteer is a NodeJS library that provides a high-level API to control Chrome or Chromium which makes it ideal for web scraping, automation, and automated testing.
TestingBot provides a grid of browsers in the cloud, always available to connect to your existing or new Puppeteer scripts. Learn more about Puppeteer automated testing.
- Powerful browser automation capabilities.
- Headless mode for fast execution.
- Supports screenshot and PDF generation.
- Limited to Chrome and Chromium.
- High(er) learning curve for beginners.
11. Nightwatch.js
Nightwatch.js is an integrated, easy-to-use end-to-end testing solution for browser-based apps and websites, using the W3C WebDriver API.
It was created by the creator of Vue.js and offers features such as Visual Regression testing, BDD Test syntax and more.
TestingBot integrates with NightwatchJS. Please see the Nightwatch documentation.
Nightwatch End-to-End Testing
Nightwatch.js excels in performing end-to-end (E2E) testing by automating browser interactions. It allows you to simulate user interactions with your web application and verify the entire workflow from the user's perspective.
Integrated Testing Framework
Nightwatch.js comes with an integrated testing framework, which means you don't need additional tools to write, manage and run your tests. It provides a clean and straightforward syntax to define tests and assertions.
Pros:- All-in-one testing framework.
- Supports Selenium WebDriver.
- Easy syntax and setup.
12. TestCafe
TestCafe is an end-to-end testing framework for web applications. It runs on NodeJS and supports all major browsers.
TestingBot integrates with TestCafe. Please see the TestCafe documentation.
TestCafe: Cross-browser Testing
TestCafe supports running tests across multiple browsers and devices. This guarantees that your application works correctly in different environments.
No Dependencies on WebDriver
Unlike other popular frameworks, TestCafe does not rely on WebDriver. This simplifies setup and eliminates issues related to WebDriver configuration. It controls the browser directly, which often leads to a faster and more reliable test execution.
Rich Selector Mechanism
TestCafe provides a powerful and flexible API for selecting elements. It supports various selector types and chaining, making it easy to target elements for testing. See the code below for a nested example with TestCafe:
import { Selector } from 'testcafe';
fixture `Rich Selector Test`
.page `https://testingbot.com`;
test('Check nested elements', async t => {
const container = Selector('#container');
const nestedElement = container.find('.nested-element');
await t
.expect(nestedElement.exists).ok()
.expect(nestedElement.innerText).contains('Hello World');
});- No browser plugins required.
- Runs tests on remote devices.
- Supports ES6+ and TypeScript.
- Limited community and plugins.
- Slower execution compared to headless frameworks.
13. WebdriverIO
WebdriverIO is a powerful and versatile end-to-end (E2E) testing framework for web and mobile applications. Built on top of the WebDriver protocol, WebdriverIO supports a wide range of browser and device automation, providing a comprehensive testing solution.
WebDriver BiDi (Bidirectional) Protocol
WebdriverIO supports the WebDriver BiDi protocol, allowing real-time communication between the browser and the automation script. This enables advanced features like console log retrieval and network interception during tests.
Chrome DevTools Protocol (CDP)
By integrating with the Chrome DevTools Protocol, WebdriverIO allows developers to access advanced browser features such as performance profiling, DOM manipulation and capturing screenshots. This provides deeper insights and control over the entire testing process.
Cross Browser Testing
WebdriverIO seamlessly integrates with TestingBot. This enables running tests across a wide array of browsers and devices in the cloud, which ensures comprehensive coverage and scalability.
TestingBot provides examples for both web testing and mobile app testing with WebdriverIO.
- Full control over browser automation.
- Integrates with various testing frameworks.
- Supports multiple services and plugins.
- Steeper learning curve.
- Configuration can be complex.
14. Protractor
Protractor is an end-to-end (E2E) testing framework specifically designed for Angular applications. It is built on top of WebDriverJS and integrates seamlessly with Angular, providing robust testing capabilities tailored to the framework's unique features.
TestingBot provides a Protractor example, showcasing how to run Protractor on a remote browser grid.
- Optimized for Angular apps.
- Supports real browser interaction.
- Integrates with existing testing tools.
- Specific to Angular, not suitable for other frameworks.
- Requires Selenium for execution.
15. Vitest
Vitest is a cutting-edge testing framework specifically designed to integrate seamlessly with Vite, a fast and modern build tool for web development. Vitest leverages Vite's performance optimizations and hot module replacement capabilities to deliver rapid and efficient testing, making it an excellent choice for developers who value speed and productivity.
Vitest: Speed and Performance
Vitest is designed for fast test execution, leveraging Vite's hot module replacement and build optimizations. This means tests run quickly, providing rapid feedback during development (shift left testing).
Seamless Integration with Vite
As Vitest is built on top of Vite, it integrates seamlessly with Vite-powered projects. This eliminates the need for additional configuration and ensures compatibility with Vite's ecosystem.
- Fast testing with hot module replacement.
- Integrates with Vite.
- Specifically tailored for use with Vite, which means it might not be the best choice for projects not using Vite.
- Vitest's community and ecosystem are not as large or established as some other testing tools.
