Difference Between Mocha And Jest Testing


Every developer is aware that application testing is an essential component of the software development life cycle. Applying the Test-Driven Development (TDD) methodology helps maintains a modular, tidy, and well-organized codebase, which is more likely to result in the creation of a high-quality software. Numerous libraries might be used to test JavaScript, however Mocha and Jest testing are two of the most widely used testing tools among Node.js developers. Which one should you select, and what are the main distinctions between them? This article discusses the differences between two. Read-on to know more:

What Is Mocha?

Your automated tests are executed on Node using the free source test framework Mocha. Mocha has several capabilities. These competencies let you build detailed automated tests, and reliable reports and even run your automated tests any time a local file is modified.

By including code and assertions to determine if a test passes or fails, we can use Mocha to run whatever kind of test we want inside describe methods. Mocha offers the framework for conducting your tests, whether they are low-level. Unit checks against back-end services or JavaScript functions or complete stack tests focusing on component integration.

After your tests all of your tests that you have built using the describe function may be executed by Mocha, which can then output the results to your console, terminal, or test report. Mocha will notify a failed test if an assertion is made. The code will also be labeled as failed if it raises an exception. It will report a pass if everything goes according to plan and all claims are true. Due to Node’s asynchronous nature, Mocha may also alert you if your test is taking an excessively lengthy time to complete.

Benefits Of Using Mocha

This section focuses on what benefits Mocha offers to the users.

  • There are several methods for providing test results in Mocha. Users may pick from a range of reporting alternatives, including the list reporter, the progress reporter, and the JSON reporter, depending on their requirements.
  • There are many installation choices. It may be set up to execute test cases directly in the web browser, as a development dependency for your project, or as a global installation.
  • Mocha offers support for many web browsers. It makes it simple to write test cases that function flawlessly in all popular web browsers. Plugins may be added to it, and Mocha updates its JavaScript and CSS builds with each new version to support more web browsers.
  • This framework also supports JS assertion libraries. It has an interoperability with a number of JavaScript assertion libraries, including Should.js, Express.js, and Chai, allowing you to cut testing expenses and expedite the process. You can construct extensive and complicated test cases more easily because to the support for different libraries; if everything goes well, you won’t need to redo them.
  • Supports environments for both behavior-driven development (BDD) and test-driven development (TDD). Mocha supports both BDD and TDD environments, making it simple to create high-quality tests and increase coverage.
  • It supports both synchronous and asynchronous testing. Mocha is built with features that call the callback once the test is complete to strengthen asynchronous testing. By leaving out the callback, synchronous testing is made possible.


Jest is a well-liked and much popular JavaScript test framework. Jest takes pride in providing a seamless and comprehensive experience. It is more comprehensive than some of its rivals since it does not depend heavily on external tools for much of its capabilities. And the lack of setting required by Jest is what makes it hassle-free and seamless. Within minutes after installing it, you may begin creating your first test.

Jest, which is used for both front-end and back-end testing, has grown significantly in popularity recently, as was indicated in the introduction. Jest is used by several large businesses, including the famous ones like Instagram, Twitter,  Pinterest, and Airbnb, for React testing.

Jest itself is a framework rather than a library. Even from the command line, you can utilize a CLI tool. As an example, the CLI tool enables you to selectively execute certain tests that meet a pattern. In addition to that, it has a lot more capability, which is documented in the CLI.

Thus, Jest provides a test runner, an assertion library, a CLI tool, and excellent support for various mocking methodologies. It becomes a framework as a result and not simply a library.

Benefits Of Using Jest

Here is a list of benefits that Jest offers to you:

  • Provides a command-line interface for simply controlling your tests.
  • It has an interactive mode that runs all impacted tests for the code changes you made in your most recent commit.
  • only and.skip, you may test a single test or skip tests. This capability comes in handy when troubleshooting specific tests.
  • It has good documentation, numerous programming examples, and a helpful community. You may join the Jest Discord group or post questions on Stack Overflow.
  • Mocking is made easier for developers, since it is one of the most difficult tasks for testing engineers. In this article, we go through how Jest mocking works in further detail.

Jest provides code coverage by default through its CLI; just use the -coverage option or the collectCoverage field in the Jest configuration file.

Differences between Mocha And Jest

Now, let’s come to the primary section of the blog where we will focus on the key differences between Mocha and Jest.

  1. To begin, Jest is intended to function as a standalone testing framework that does not need any extra dependencies. Mocha, on the other hand, requires a number of libraries to be integrated in order to function effectively. As a result, a developer must declare which assertion, mocking, or stubbing library will be used in the project. Furthermore, Mocha does not define any hard prerequisites for configuring these libraries together and is recognized as a more efficient tool, resulting in speedier test execution.
  2. Coming to the second point that we must consider is that Jest is often regarded as a ‘easy to use testing tool, which may be advantageous for developers who have just recently began using the TDD technique. Furthermore, Jest does not allow logical conjunctions or disjunctions, but Mocha (when used with the Chai assertion library) does.
  3. Mocha is a well-established testing tool that has been in use for many years. It has a significant user base and is well-supported. Jest is a recent tool developed by the Facebook team. It offers many of the same features as Mocha as well as some distinct benefits. Jest is also more rapid than Mocha. It has snapshot testing capabilities, which implies that tests are automatically executed when the code is changed. This makes it simple to maintain your tests current as you work.
  4. When it comes to simplicity of use, Mocha is a bit more difficult than Jest. Jest is intended to be easy and uncomplicated, while Mocha has more choices and might be more challenging to master. Mocha, on the other hand, may be very potent if used correctly. Because Mocha is a more established program with a bigger community of developers, it includes more functionality out of the box. If you desire a certain feature, chances are someone has already done it. If the functionality is not currently accessible, you may need to utilize a plugin or create your own.
  5. Mocha and Jest are both excellent tools for doing JavaScript testing. Jest has a more simplistic approach, while Mocha comes with more functionality out of the box.
  6. Jest has fewer features than Mocha and does not support several useful features such as asynchronous testing. Nonetheless, one of its most enticing characteristics is its simplicity. Jest may be a better choice if you need a lightweight, uncomplicated testing solution.
  7. Asynchronous testing is supported by Mocha through the done() callback. Jest, on the other hand, performs tests after each modification to guarantee they are up to date. Many users remark that approach cuts development time in half.

Which Do You Prefer, Jest Or Mocha?

Both Mocha and Jest have benefits and disadvantages, thus, selecting between them is dependent on the projects they will be used for as well as a grain of personal choice.

  • If test running speed is the only consideration, the Jest runner’s better speed will suffice.
  • Large back-end applications may benefit more from Mocha’s setup and ad-hoc external library selection flexibility.

Likewise, if the aim is to get started quickly with a few tests on a small project, Jest’s no-setup-required approach might be a winner. Overall, there seems to be a lot of affection for both Mocha and Jest.

As web application development becomes more dynamic, developers are required to offer an improved version of the program in shorter release cycles. Because testing must coincide with development velocity, it is rational for developers to seek solutions that can make their work faster, efficient, cost-effective and more reliable.

One such tool is LambdaTest. It is a scalable, cloud-based and a cross-browser testing platform that allows you to execute your Selenium automation scripts on an online Selenium Grid on 3000+ different virtual browsers and OS systems. So you can now easily execute your JavaScript automation testing test cases on a scalable Selenium infrastructure.

LambaTest supports test automation with popular automated testing tools and frameworks. This will accelerate your time-to-market. The good news is that LambdaTest supports all test frameworks, including Jest and Mocha. The platform offers the infrastructure for you to run your automation tests and guarantee that your development code displays well using an on-cloud Selenium Grid. Furthermore, parallel testing allows you to significantly reduce your testing cycles.


Which framework will work best for you is totally based on the requirements of your project. Mocha is arguably the best solution if you have a huge project that requires flexibility and customization. Jest is definitely the best alternative if you have a smaller project and do not require the additional setup and configuration up front. Which framework will be the best answer for you and your team is entirely up to you.

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