Testing is one of the most important skills as a Software Developer! It improves your bug-free code's quality and makes the program much less likely to have bugs. On top of that, it's very convenient to make refactoring possible, which improves your lines of code maintainability!
The vast world of Software Testing falls into two types: manual and automated. Yet, you might have also heard about unit, continuous integration, and snapshot testing. This article will focus on popular frameworks TS developers use to test and perform automated testing. Let’s put it to the test!
What is Unit Testing?
Unit testing libraries consider small units to ensure that everything does what you expect. What is critical here is that there must not be any communication between the unit and any other piece of code.
In other words, the test must not connect to a database or receive compatible API calls or any external dependency injections. That allows you to address bugs in your configuration files quickly. In this manner, unit testing improves your code's quality and maintainability.
What is TypeScript Unit Testing?
We've already discussed the power of TS is, specially when compared with JS: it provides all JavaScript features but with extra benefits.
Among what makes it a superset of JavaScript, there is its IDE support, static typing, better code readability, and developer tooling. As a result, you're less likely to make mistakes, which means you might not need as many tests.
TypeScript comes with all the greatness of JavaScript and its frameworks which, of course, includes all testing frameworks. You'll also be happy to hear that Visual Studio supports the most popular ones!
Best TypeScript Unit Testing Frameworks
Jest for Unit Testing
Let's begin with one of the most popular frameworks, Jest. A key reason as to why it's one of our favorites is that its perfect for testing React web apps!
It's also easy to integrate with powerful JavaScript tools, like Babel, Webpack, and ESLint, to develop a product. The best part is that it also does wonders with Node and Vue.
Jest requires zero configuration and can execute multiple tests in parallel so that it might be a great choice for larger projects. As a result, it streamlines the testing process to a large extent, making it fast and smooth.
Vitest for TypeScript Unit Testing
Launched in 2022, Vitest is often seen as a improved version of Jest. It comes with all of Jest's key built-in features and power and included workspace and out-of-the-box TypeScript support, which often makes it better suited for modern products.
It even has Jest-compatible Snapshot along with Expect and coverage! Plus, Vitest makes migrating from Jest a straightforward process.
Storybook for Unit Testing
This framework goes for our UX/UI-savvies! With a stunning visual interface, Storybook strongly focuses on UI components in isolation. With it, you can inspect and debug UI components without logic or app context interference. That's key in a landscape with so many user interfaces!
In fact, its name comes from the fact that it can save every subtle UI variation as a "story." You can access those stories and use them in both dev and testing. Storybooks help simplify the increasing complexity of web development, and when it comes to TypeScript, it also has a zero-configuration setup.
Mocha for Unit Testing
You probably know Mocha, and you'd also know that it's often used for more complex projects than the previous frameworks. Mocha is a robust framework that allows you to work with external assertion libraries like Chai.
Moreover, Mocha tests run sequentially, offering more flexibility, supports asynchronous testing, and furthers Test-Driven Development. One last advantage we can’t overlook is its report accuracy, which comes in handy when tracking test coverage and failing tests.
Tip: If you’re using Mocha or Jasmine, you must type ts-node to add TypeScript support to your test suite. If you're using Jest, you must start with ts-Jest. You would likely also place source JS/TS in the src folder and test files in the test folder.
Conclusion
On the one hand, Jest is highly effective for running parallel testing units of code. Since most devs use it, you'll likely need some familiarity when joining a project. Yet, on the other hand, Vitest strongly focuses on cutting-edge products. Likewise, both Mocha and Storyboard have core features that help ensure top-notch code quality for full-stack projects. Make sure to consider all edges to make a smart choice alignes with your dev requirements!
