Jest offers a lot of functionalities for mocking functions and spying on them. Unfortunately, there are some pitfalls we need to watch out for. In this article, we explain how spying on functions works. We also explain how and why we should reset our mocks. Creating mock functions The most straightforward way of creating a […]
In the fourth part of this series, we’ve learned the basics of mocking API calls. However, there are often situations where we would like to test various more demanding cases. So, in this article, we implement more advanced examples on how to mock with Jest. Creating a simple React component Let’s start by creating a […]
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In the previous part of this series, we’ve focused on unit tests. This time, we look into integration tests. In this article, we explain their principles and how they differ from unit tests. We write a few of them using Jest to test our services. We also look into the SuperTest library to test our controllers. […]
Cypress has proven to be an appropriate tool for writing E2E tests. In the previous parts of this series, we’ve gone through its basics. That’s a proper moment to take a look at a useful addition: the Gherkin syntax. In this article, we look into its principles and how to make a Cypress Cucumber integration. […]
In the previous part of this series, we’ve learned the basics of the Cypress framework. Although the above knowledge is enough to write our first tests, there is much more to explore. In this article, we dive a bit deeper into the mechanisms of Cypress. By doing so, we can avoid some troubles along the […]
So far, we’ve covered quite a lot of different types of tests. Some of them were unit tests or integration tests, where we tested a specific part of our implementation or components working together. In this article, we look into End-to-End testing and perform it using the Cypress framework. The principles of the End to End (E2E) testing The […]
The hooks are an exciting addition to React and undoubtedly one that helps us to separate the logic from the template. Doing so makes the above logic more testable. Unfortunately, testing hooks does not prove to be that straightforward. In this article, we look into how we can deal with it using react-hooks-testing-library. Identifying the tricky […]
A common thing is for our application to fetch some data from the API. A problem with it is that might fail for various reasons, such as the API being down. We want our tests to be reliable and independent and to ensure that we can mock some of our modules. Mocking For the purpose […]
Hello! In the previous part of the tutorial, we’ve covered the very basics of testing React components with Enzyme. Today we will dig a bit deeper and learn how to test props, how (and why) use the mount function and what are the snapshot tests. Let’s go! Testing props In the previous article, we’ve tested […]
At the previous part of the tutorial, we’ve briefly covered the basics of unit testing. This time we will go further and start testing React with the Enzyme library. Thanks to the that, your application will be more reliable and it will be easier to avoid regression. Even though we will be using Jest here, Enzyme also works […]
