8 Best JavaScript Unit Testing Frameworks and Tools

With growing demand & popularity of smartwatches, mobile-first approach, and devices with varying display resolutions, it is evident that the landscape of web development is dynamic, and has revolutionized Front-endFront-endFront-end web development is the practice of converting data to a graphical interface, through the use of HTML, CSS, and JavaScript, so that users can view and interact with that data. development in the recent past. 

We have witnessed a shift in the paradigm of coding and developing websites and web apps. Over the past decade, it was evident that we have moved on from the long-used conventional programming languages such as PHPPHPHypertext Preprocessor, fondly called as PHP, is one of the widely used open source scripting language mainly focused on web development which can be embedded into HTML. In addition, it acts as a server-side scripting language as well as a general-purpose programming language., ..NET.NET.NET was developed by Microsoft to provide interoperability across several programming languages. .NET is basically a software framework that runs on Microsoft Windows. It comes with the Framework Class Library, a large class library, which enables .NET to provide the interoperability feature. , JavaJavaJava is one of the majorly used general-purpose programming language designed to have no or limited implementation dependencies. Java requires a software platform for its compiled programs to be executed. Oracle and Android SDK are a few examples of the software platforms on which Java executes its programs., etc.

This shift in web development demands exceptional testing tools to avoid bugs in the code. Have you ever wondered – What is the best JavaScript testing framework? Here are some of the best unit testing frameworks for JavaScriptJavaScriptJavaScript, often abbreviated as JS, is a high-level, interpreted scripting language that conforms to the ECMAScript specification. JavaScript has curly-bracket syntax, dynamic typing, prototype-based object-orientation, and first-class functions. predominantly used in the IT space.

What is Unit Testing? Why Should you use Unit Testing?

Unit Testing is a Software TestingSoftware TestingSoftware testing is a chain of interlinked processes and it is quite broad. The software’s health and the completeness of core requirements are tested in the process. The testing process involves identifying technical bugs and errors and ensuring that the software is error-free. method, where you can check for bugs in your code at the module level. It helps you keep track of the modules and align them with the business document specifications. 

Respective test codes are written while developing each module. Now, with every new module development, the test codes are run to ensure the newly developed modules don’t affect the existing modules.

The selection of the right development tools and unit testing tools is of paramount importance as JavaScript development could get messy. The front-end testing frameworks focus on ensuring the responsiveness and usability of the app. 

1. JEST – Works with Projects Using Babel, TypeScript, Node.js, React, Angular and Vue.js

JEST is an open-source JavaScript testing framework created and maintained by developers at Facebook and a community of open-source contributors. Since it requires no configuration, developers choose this framework without any dilemma for React-based apps. However, you can use this framework with TypeScript Node.js, AngularJS, etc. 

Highlights of JEST:

• Single framework for Node.jsNode.jsNode.js is a cross-platform runtime environment used to develop server-side and networking applications. It is an open source platform and the applications are developed using JavaScript. It can run within the Node.js runtime on Microsoft Windows, Linux, and OS X., ReactReactReact is a JavaScript library for building user interfaces. It is maintained by Facebook and a community of individual developers and companies. React can be used as a base in the development of single-page or mobile applications, as it is optimal for fetching rapidly changing data that needs to be recorded., Angular JSAngular JSAngularJS is a JavaScript-based open-source front-end web framework mainly maintained by Google and by a community of individuals and corporations to address many of the challenges encountered in developing single-page applications.,Vue.jsVue.jsVue.js is an open-source Model–view–viewmodel JavaScript framework for building user interfaces and single-page applications.& Babel-based projects.
• Snapshots help you perform tests, which keeps track of large objects with ease.
• Well documented and standard syntax of coding
• It has the entire toolkit in one place.

2. AVA – Test Runner for Node.js with a Concise API

AVA is a light-weight framework that takes full advantage of JavaScript’s asynchronous nature. It runs tests faster and performs them concurrently and asynchronously. AVA is majorly implemented to run tests on Node.js-based codes. 

It delivers detailed error output, embraces new language features, and process isolation that lets you write tests more effectively. 

Highlights of AVA:

• Simpler syntax for JavaScript tests
• Faster than most of the other test frameworks
• Runs tests concurrently and asynchronously 
• Cleaner stack traces for any potential errors that are detected

3. Mocha – A Feature-rich JavaScript Test Framework Running on Node.js and in the Browser

Mocha supports both front-end and back-end testing of JavaScript codes on the browser or Chrome engine. It helps you develop tests on-the-go as per your requirement. Also, it will run the tests asynchronously on your browser & Node.js runtime environment.

Highlights of Mocha:

• Supports Node.js debugger
• Supports object mocking to do flexible back-end tests
• Provides a clean base to develop tests as per your convenience
• Supports all browsers and even headless chrome library

4. Karma – Karma is a Test Runner for JavaScript that Runs on Node.js

Karma is a testing environment developed and maintained by the AngularJS team. It supports all popular testing frameworks within it. It lets you test your code on browsers and devices such as phones, tablets, or on a headless PhantomJS instance.

Out of all, the predominant feature of Karma is, it lets you integrate with CI/CD (Continuous Integration / Continuous Delivery) engines.

Highlights of Karma:

• Supports tests written in most of the popular frameworks
• Supports test case debugging using Chrome as well as Webstorm
• Can be used to run tests on browsers, headless environments like PhantomJS, and also on devices

5. Puppeteer – A Node.js Library Maintained by Chrome’s Development Team from Google

Puppeteer is a test execution framework, developed by one of Google’s teams. It offers a high-level API to control headless Chrome for Node.js apps. 

It is predominantly used to perform different tests on web apps such as page structure test, capturing screenshots, crawl test, and also, capturing pre-rendered content for single-page apps (SPA).

Highlights of Puppeteer:

• Supports ES6 functionalities such as async and await.
• Can be extended to test chrome extensions
• Ability to set custom resolutions and sizes for the browser
• Automation support for form submission, UI testing, and keyboard inputs

6. Jasmine – An Open-source Testing Framework for JavaScript

Jasmine is a behavior-driven development framework for testing JavaScript code. It does not depend on any other JavaScript frameworks and doesn’t require a DOMDOMThe Document Object Model is a cross-platform and language-independent interface that treats an XML or HTML document as a tree structure wherein each node is an object representing a part of the document. The DOM represents a document with a logical tree.. Also, it has a clean syntax so that writing test codes are no more a hassle for you. 

It ensures, click clarity, responsiveness, and visibility. Moreover, you can replicate user behavior with specified delays and waiting time.

Highlights of Jasmine:

• Supports front-end as well as back-end tests
• Lowers overhead due to almost zero external dependencies
• Codes are written similar to natural language
• Comes packed with almost every required tool 
• Extensive documentation to use it with several frameworks

7. Cypress.io – An Open-source End-to-End JavaScript Testing Framework for Writing and Automating UI Tests

Cypress IO offers a fast, easy, and reliable testing in a web browser. It has an interactive UI on the web browser in the form of a web page & you can install it on Mac, Windows, and Linux. Also, you don’t have to integrate your code closely with the test runner.

Highlights of Cypress.io:

• Cypress is based on a completely new architecture and not Selenium.
• Cypress has been developed dedicatedly for developers and QA engineers.
• Installing is Easy: No dependencies, extra downloads, or changes to your code required.
• Lets you write and execute tests easily and quickly in real-time as you build your web app.

8. QUnit – A Powerful, Easy-to-use JavaScript Unit Testing Framework

QUnit is a robust JavaScript testing framework for front-end development. Developers go ahead with QUnit for jQuery, jQuery Mobile, and jQuery UI libraries. The best part about QUnit is that it can be written separately and executed on any webpage. All you have to do is to include the file onto the webpage and run tests with the help of the QUnit plugin.

Highlights of QUnit:

• Offers a ready-to-deploy web interface to view test case outputs
• Can be used to build reusable test scripts
• A host of plugins built on top of it enables faster test case development

Unit testing for javascript helps in ensuring the code changes don’t affect the web app and continues to work seamlessly as per business requirements. Hence, unit testing for javascript helps you develop and test web apps on-the-go without much hassle.

We, at TechAffinity, have a dedicated team of testers and quality analysts to control the quality measures of the web apps developed. Our experts ensure there is no code redundancy in your web app and is ready for launch. Get in touch with us by scheduling a meeting or drop an email at media@techaffinity.com.