JavaScript unit testing frameworks in 2022: A comparison

It also has an inbuilt test runner that can run tests in both browsers and Node.js directly from the command line. These tools launch and execute all your test cases and produce the results. For particularly JavaScript, you can launch tests in various environments like browsers, headless browsers, or Node.js.

Unit Testing Frameworks in Selenium This guidepost highlights some of the highly preferred language-specific unit testing frameworks in … However, the complex setup process of Mocha has now made it less popular as other zero setup frameworks have emerged in popularity. Many teams also like Mocha as a way to provide a clean base for writing test cases. After looking at eight of the many options available for the JavaScript unit testing framework, it is clear that choosing one of them all is not as easy as it sounds.

Playwright can also be used with major CI/CD servers like TravisCI, CircleCI, Jenkins, Appveyor, GitHub Actions, etc. Playwright is another automation framework that works best for E2E testing. This framework is built and maintained by Microsoft and aims to run across the major browser engines – Chromium, Webkit, and Firefox. Testing Library is a set of tools and functions which help you access DOM and perform actions on them, ie rendering components into Virtual DOM, searching and interacting with it. For smaller projects which don’t include sophisticated assertions or testing logic, Mocha is a simple solution. For any application with a web experience, JavaScript is going to be a part of that application in some way.

Screenshots can be taken in different browsers and across different screen sizes to ensure consistent cross-browser and responsive styling of your application. Parallel Testing- TestCafe can run your tests on several browser instances at once. This practice can significantly decrease your testing time. TestCafe injects itself into the website as JavaScript scripts instead of controlling the browsers themselves like Selenium does. This allows it to run on any browser, including on mobile devices, and have full control over the JavaScript execution loop. Framework- Can be used with other frameworks too, but can be especially useful in case you want to run E2E tests, not as part of another framework.

“RhUnit – A QUnit compatible Javascript unit testing framework for Rhi…”. It has been around for longer and it has a huge amount of articles, tools, and questions answered in various forums that were all created by the community over many years. One for running unit and integration tests and another one for E2E Tests. This is because functional tests usually take much longer to run, especially when running the test suite on several different browsers. Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun.

After that, Jest will check the app and execute testing whenever you make any changes in the code. You may wonder, “Why did developers and testers vote Jest as the best framework? Other popular frameworks are Jasmine, Testing Library, and many more. After looking at just a few of the many frameworks out there, it’s pretty clear that choosing a framework isn’t black and white.

Node.js library for comparing images. Contribute to gemini-testing/looks-same development by creating an account on…

Even if you believe your business logic is “mostly” on the backend, it’ll be remiss to skip having any test infrastructure for your JavaScript codebase. Hiring IT Staff Augmentation USA resources brings greater productivity and speed to projects. Along with the above facts, let’s explore the various benefits of unit tests.

js unit testing framework

Jest is a highly preferred framework for applications based on React. It provides a straightforward and very convenient user interface. This framework comes bundled with exciting features like snapshot testing and a built-in tool for code coverage. There are also a Coding Salary: How Much Do Computer Programmers Make lot of resources available online that can be used to validate almost everything around JavaScript, especially the browser rendering of web apps. There are several best JavaScript unit testing frameworks that you can choose from, including those mentioned above.

Development- jest only updates the files updated, so tests are running very fast in watch mode. Reliability- Since it has a huge community, and used in many very complex projects, is is considered very reliable. Performance- First of all Jest is considered to How Long Does It Take to Learn to Code be faster for big projects with many test files by implementing a clever parallel testing mechanism. It was initially based on Jasmine which I will discuss later. Over time, Facebook replaced most of its functionality and added a lot of features on top of it.

chai — BDD / TDD assertion framework for node.js and the browser that can be paired with any testing framework.

JavaScript is one of the most popular programming languages ​​among application and website developers. It can be defined as a high-level, dynamic, interpreted language used with HTML web applications. It is also used for non-web documents, such as PDF files and desktop widgets. But whichever top testing framework you choose, you’ll need great JavaScript developers to make the most of it.

  • You can’t afford to release a bug-ridden codebase only to recall it later and suffer immense financial and reputational damages.
  • It works entirely in Chrome, Firefox, and Edge without needing an external driver binary.
  • After every new module development, the entire suite of test cases is run to ensure that no existing modules are affected by the developed module.
  • WebdriverIO leverages the power of the WebDriver protocol that is developed and supported by all browser vendors and guarantees a true cross-browser testing experience.
  • It includes both visibility testing and the responsiveness testing of UI across various devices with different resolutions.

From zero to run, Cypress contains all the necessary information to get you up to speed. Up until v6.0.0, Mocha had a feature which allowed you to use an arbitrary transpiler like coffee-script etc, but it’s now deprecated. If you want flexible configuration, including node js How update node 12 to 16 version in angular project your preferred libraries, then the additional set-up and configuration of Mocha is something you definitely need to check out. When you import your libs in your test files, Jest auto-mocks those libraries to help you work with them more easily and avoid boilerplate.

Understanding JavaScript Design Patterns In Depth

But the key difference between the two is that Cypress doesn’t need to integrate with your code. Not only that, unit testing helps you find bugs early in the development cycle. If you’re a developer, finding and fixing the bugs by yourself will improve the code quality and make the testing phase easier. You have to include additional libraries for assertions, and this does mean that it’s a little harder to set up than others. That said, set-up is generally a one-time deal, but it’s nice to be able to refer to a “single source of truth” instead of jumping all over the show. The second most-used library, Mocha is only a test framework and provides developers with just the base test structure.

js unit testing framework

Hosted on Github, Mocha is recognized for its flexibility, and as a result, it has proven to be one of the most dependent libraries among JavaScript developers. Chromatic is a visual testing tool for Storybook made by Storybook maintainers. Techniques and integrations to automate the browser or to run as part of E2E Testing tools discussed above, including in the CLI for CI. Using Mocha as the test structure provider makes its use pretty standard and allow your E2E tests to be built in the same structure as the rest of your tests.

simple, flexible, fun javascript test framework for node.js & the browser

This page can be run across many browsers and browser-like environments including jsdom. While not, strictly speaking, a testing tool, Storybook lets you write components in special “stories” which enable developing and interacting with components in isolation. Jsdom is a JavaScript implementation of the WHATWG DOM and HTML standards. In other words, jsdom simulates a browser’s environment without running anything but plain JS. Component snapshot tests fall into this category as well.


It’s no surprise that it was identified as the most popular unit testing framework in the 2020 survey done by the State of JS. It has a simple API while still supporting advanced features. It achieves its blazing speed by running tests in parallel as separate Node processes.

Run your browser tests and Node.js tests with the same framework. It is used to create many of the websites and apps you use every day. The trade-off is that since tests are run in V8 without a browser, there is no DOM available. You can still use Google JS Test for tests of DOM-manipulating code however; see “Is it for me?” for more details.

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