Developing powerful and reliable JavaScript applications requires a robust testing architecture. Choosing a suitable framework is an early and vital step in your project. This article delves into the top JavaScript unit testing frameworks for 2022. We’ll review their strengths, weaknesses, and ideal use-cases. We will cover Jest, Mocha, Storybook, Cypress, Jasmine, Puppeteer, Testing Library (React), WebDriverIO, Playwright, Ava, and Vitest.

Understanding The Landscape With Stateofjs

Stateofjs.com collates data from thousands of web developers annually. It provides a valuable resource for understanding trends and popular tools in the JavaScript development landscape. Let’s use the most recent findings to guide our discussion.

1. Jest

Jest provides a comprehensive suite of testing tools with clear documentation that makes it easy for developers to get started.

const sum = require ('sum')
test ('adds 1 + 2 to equal 3', expect(sum (1, 2)).toBe(3));

Pros

• Solid performance levels making Jest excellent for continuous deployment.
• Highly compatible with Angular, Node, Vue, and Babel.
• Supports auto-mocking and wide API including timer mocks.
• Lively community and active ongoing development.

Cons

• Slow runtime due to auto-mocking feature.

2. Mocha

Mocha offers you the flexibility to structure your tests and choose your assertion library. It provides support for ES modules.

var assert = require ('assert')
describe('#indexOf()', function() {
   it('should return -1 when the value is not present', function(){
        assert.equal([1,2,3].indexOf(4), -1);
   });
});

Pros

• Lightweight and simple to use.
• Offers a flexible configuration.

Cons

• Setting up Mocha can be quite challenging.
• Potential inconsistency with plugins.
• Compared to its counterparts, its documentation is less robust.
• Older versions do not support arbitrary transpilers.

3. Storybook

Storybook supports visual, interaction, accessibility, and even snapshot tests.

Note:

Due to its unique capabilities, comparing Storybook directly with others in this list would not give an accurate representation. You might need to research more to ascertain how it would fit into your project.

4. Cypress

Cypress is known for its E2E testing and timeline snapshot testing features.

describe('Actions', () => {
  ...
  it('type – type into a DOM element', () => {
     ...
     cy.get('button').type('hello, world', { delay: 100 });
  });
});

Pros

• Reliable and steady performance.
• Detailed documentation and fast execution.

Cons

• Lacks multi-browser support.

5. Jasmine

Jasmine is excellent for test-driven development (TDD).

describe('helloWorld', function() {
    it('returns hello world', function() {
        var actual = helloWorld();
        expect(actual).toBe('hello world');
    });
});

Pros

• A straightforward API that simplifies writing unit tests.
• Jasmine is a synonymous term with “batteries-included”.

Cons

• Global environment pollution.
• Challenges in async testing.

Tags

• JavaScript Unit testing, Jest, Mocha, Cypress, Storybook

  Reference Link