How to write tests for Node.js?

Sunscrapers Team

27 December 2022, 6 min read

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What's inside

  1. Intro
  2. Mocha
  3. QUnit
  4. Jasmine
  5. Jest
  6. Chai
  7. Mockery
  8. Jenkins
  9. Summing up
  10. Contact us
  11. Read more


Testing is a crucial part of software development - no doubt about it. Without it, bugs creep into the wild, where they are harder and more expensive to fix. Test automation carried out by both developers and testers can significantly increase the scope of tests and reduce long-term costs, depending on a specific company’s manner of work. They can be divided into unit tests, i.e., concise tests targeting very small pieces of functionality or larger integration-level tests.

Either way, identifying and integrating automated testing tools into your Node.js environment can be somewhat daunting. That’s why we will cover a few popular tools and provide an overview of how to integrate them to create a comprehensive testing environment.


First, we’d like to discuss Mocha - a framework focusing on BDD testing and fluent notation. A substantial advantage of this environment is the ability to use any library responsible for building assertions, e.g., Should.js, Expect.js, Chai, and better-assert.

Some of the most important features of Mocha are

  • Free choice of assertion library.
  • Very good and easy support for asynchronous tests.
  • Determination of slow-running tests.
  • The ability to set time-outs for tests (also asynchronous).
  • Test coverage reporting.
  • Efficient integration with Node.js.


The team behind the QUnit is also the one that developed the jQuery library. Since its creation, the framework has grown so much that it is now a separate testing environment and does not require the jQuery library to function.

By design, the QUnit framework provides a minimalist API that allows you to write unit tests in a simple way.

Its core features are

  • Minimalist and at the same time easy to use API, making it one of the most friendly testing frameworks.
  • Asynchronous testing.
  • Support for running tests as part of Continuous Integration.
  • Independence from jQuery and other libraries.
  • Assertions built-based on the CommonJS Unit Testing specification (by installing the SpecIt library, we can change it to fluent notation).
  • Adaptation to regression testing.


Jasmine is a testing framework written in the spirit of behavior-driven development. There are no additional dependencies, and, as the creators claim, it comes with batteries included which means it should contain everything needed to write unit tests for a particular project.

Let’s take a look at its characteristics

  • Testing any JavaScript code, both in the browser and on the server.
  • More fluent syntax of writing tests.
  • As it tries to resemble natural language, at first, it may be challenging to grasp, but after mastering it theoretically, the tests should be much more understandable.
  • It’s a more extensive framework that includes built-in constructs to handle stubs and mocks.


Although Jest created by Facebook is a library that is mainly associated with frontend, and especially with applications created in the React framework, it also works well in Node.js apps.

  • Its syntax is very similar to other tools, that’s why switching from an existing solution shouldn’t be a problem.
  • It works well in projects that need to be delivered quickly, and there is no time to compose a development toolkit.
  • Using Jest efficiently speeds up the entry - most of the necessary elements needed to write fast and effective tests are already in place. No need to search for more plugins and libraries.


Chai is an assertion library that allows you to use natural language constructs when creating tests. This is extremely helpful, as many confirmation libraries can be quite cryptic.

  • It can be easily paired with any JavaScript testing framework.
  • It’s composed of several interfaces, which allows a developer to choose the most convenient option.
  • The chain-capable behavior-driven development style guarantees an expressive language & readable style.
  • The test-driven development assert style provides a more classical feel.
  • It’s used by companies such as Lunchbox, QualityMinds GmbH, and The Lonero Foundation.


Mockery is a small npm module that allows you to replace test mocks without modifying the production code. By simply creating a dummy function or module and registering it with a mock, Node.js will inject your mocks wherever a required statement is used in your code.


Jenkins is a continuous integration system that can hook into version control (e.g., git) and automatically do a mocha every time a commit happens. This means that your product is tested every time there is a change submitted by developers.

  • Full automation of all processes: building a project, execution of unit tests, performing integration tests, as well as building and deploying applications.
  • It can be run on a local machine, in the Cloud, or using Docker, without compiled steps we.
  • Vast selection of plugins allows us to integrate with many tools that will support our work.
  • The possibility of work in dispersion - we can have many machines on which we will distribute the work of the system, thus accelerating the compilation, testing, and deployment of the final application on many platforms.

Summing up

After getting to know the most popular types of frameworks used in tests for Node.js, you may be a bit confused about which tool may be best for your project. It all depends on what we want to test, how much time we want to spend on testing, and our budget.

Considering all these factors, a quality assurance expert from Sunscrapers can choose the most suitable testing framework that will work best for you and your project.

Contact us

At Sunscrapers, we have a team of developers and software engineers with outstanding technical knowledge and experience. We can build your project successfully.

Talk with us about hiring Python and Django developers and work with the best. Sunscrapers can help you make the most out of Python, Django, and other technologies to put your project to the next level.

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Read more

  1. Python vs Node.js - which backend technology is for you?
  2. Which framework to choose - Django or Node.js?

Sunscrapers Team

Sunscrapers empowers visionary leaders to ride the wave of the digital transformation with solutions that generate tangible business results. Thanks to agile and lean startup methods, we deliver high-quality software at top speed and efficiency.




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