Most developers nowadays combine JavaScript, HTML5, and CSS3 to create responsive web applications that deliver richer user experience across small and large devices with a single code base. Many web developers also leverage Node JS – a cross-platform runtime environment – to write server-side code in JavaScript. The developers need to test the JavaScript applications with varying devices, operating systems, and browsers to measure their user experience.

The JavaScript testing frameworks make it easier for testing professionals to perform and repeat a variety of tests across browsers. Some frameworks even accelerate JavaScript application testing by providing both test environment and testing structure. The testers can also use the frameworks to generate, display, and monitor test results efficiently. A web developer has option to choose from a wide range of open source JavaScript testing frameworks. But the experienced web developers always opt for these specific JavaScript testing frameworks.

Brief Overview of 8 Widely Used JavaScript Testing Frameworks

1) MochaJS

The open source testing framework enables developers to evaluate both synchronous and asynchronous code. The testing professionals can further run Mocha on both web browsers and NodeJS.  They can even install and use Mocha in a number of ways. Hence, it becomes easier for testers to assess the quality of JavaScript code and develop and execute test scripts.

The testers can even use the testing framework in both test driven development (TDD) and behaviour driven development (BDD) environments. In addition to providing a robust test environment, Mocha is also compatible with several popular JavaScript assertion libraries. But it requires testing professionals to set up the assertion liabilities and mocking utilities separately.

2) Jest

Facebook recommends testers to evaluate React applications with Jest. Despite being developed as an easy-to-use JavaScript testing solution, Jest accelerates web application testing by providing a set of tools and facilitating snapshot testing. It further speeds up JavaScript testing by allowing testers to run tests in parallel across workers.

The testers can easily assess the test results in the form of buffered and integrated console messages. Like Mocha, Jest also provides both testing environment and testing structure. But it makes it easier for testers to compare different test runs by capturing snapshots of components and data structures.

3) Jasmine

Jasmine is designed as a behavioural-driven testing (BDD) testing framework for JavaScript. But it implements batteries-included philosophy, and enables testers to evaluate JavaScript applications without using any third-party tools. The testers can even use Jasmine to run both web browser tests and NodeJS tests.

The simple and human-friendly syntax provided by Jasmine helps testing professionals to keep the JavaScript code clean, readable, and maintainable. The users even have option to integrate a Jasmine with a number of widely used web frameworks and continuous integration (CI) servers. But they lack the option to work with other JavaScript assertion libraries.

4) Tape

Tape is designed as a “tap-producing harness” for both NodeJS and web browsers. It simplifies JavaScript testing by supporting the TAP (test any protocol) principle. The testers can use Tape to test JavaScript applications without using assertion libraries and external dependencies additionally.

Tape further implements a number of JavaScript coding best practices including avoid using global functions. The testers can further load some of the required modules before executing test. But Tape does not allow testing professionals to run asynchronous test cases concurrently.

5) QUnit

The unit testing tool for JavaScript is currently used by widely used JavaScript libraries like jQuery UI and jQuery Mobile. The testing professionals can use QUnit to test any generic JavaScript code. QUnit further supports NodeJS along with several modern web browsers. Hence, the testers can run the unit testing framework seamlessly on NodeJS and web browsers.

In addition to being designed as an easy-to-start JavaScript testing framework, QUnit further executes tests in the order they have been added to the test suite. As QUnit was initially a part of jQuery, it become easier for testers to evaluate DOM events and elements. However, QUnit does not support source maps and asynchronous operations.

6) Nightwatch

The continuous integration and automated testing framework for JavaScript is developed based on NodeJS. But the users can run Nightwatch against Selenium WebDriver Server. It makes it easier for testers to write test scripts by providing simple syntax. The testers can use Nightwatch to write tests quickly with JavaScript and CSS.

Also, they can run the tests in parallel or sequentially through a built-in command-line test runner provided by the framework. They can further extend Nightwatch according to precise project needs by running flexible commands and integrating with assertions libraries. Nightwatch can even be integrated with various continuous integration systems and cloud testing solutions.

7) Cucumber

Cucumber is designed as a behaviour-driven testing framework for JavaScript. But it enables JavaScript programmers to run readable automated tests written in plain language. In addition to merging specification and test documentation, Cucumber also keeps the specifications up to date. At the same time, the open source framework facilitates close collaboration between various stakeholders in the project by generating executable specifications.

The tools provided by Cucumber further enable testing professionals to produce accurate test results without putting extra time and effort. The QA testers can even run Cucumber on both web browsers and NodeJS.

8) Karma

Karma is designed with features to simplify and speed up test driven development (TDD). The web application testers can use Karma to execute JavaScript code in a number of real browsers. Hence, it becomes easier for them to test the JavaScript code and produce reliable test results. In addition to allowing testers to run JavaScript code in real web browsers, Karma also supports widely used browsers like Chrome, Firefox, Internet Explorer, Safari and Opera.

It even allows testers to run tests on continuous integration servers and execute the test locally. The users even have option to integrate Karma with popular JavaScript testing frameworks like Jasmine, Mocha, and QUnit through specific plug-ins.

On the whole, the software QA testing professionals have option to choose from a wide range of JavaScript testing frameworks. These open source testing frameworks help testers to test JavaScript applications without increasing project overheads. But each JavaScript testing framework has its own pros and cons. For instance, some of these frameworks run only on web browsers, whereas others run on both NodeJS and browsers. Hence, it becomes essential for testing professionals to compare these widely used JavaScript testing frameworks based on specific needs of each project.