Every automated test that we write should be deterministic. One of the things we need to do to achieve that is to make our frontend tests independent of the backend. Besides mocking REST API requests, we also need to learn how to mock a WebSocket connection. In this article, we create a simple backend application and […]
When working on web applications, we often display lists of data. If the data is not particularly lengthy, we are probably okay with rendering all elements at once. However, as our data grows, we might notice performance issues. In this article, we create a simple React application that aims to render thousands of images using […]
React Hook Form is a popular library that helps us deal with forms and keep their code consistent across the whole application. In this article, we look into how to allow the user to shape the form to some extent and create data structures that are recursive. In the end, we get the following form: […]
Formik is a popular tool that helps us write React forms and keep their code consistent across even big projects. Besides having a fixed number of properties, we sometimes need to allow the user to shape the form to some extent and create recursive data structures. In this article, we learn how to do that […]
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 […]
When developing applications, data fetching is one of the most fundamental tasks. Despite that, there are some things to watch out for: one of them is race conditions. This article explains what they are and provides a solution using the AbortController. Identifying a race condition A “race condition” is when our application depends on a […]
A few days ago, React released version 18, which is not compatible with Enzyme. Furthermore, it probably is not achievable to use Enzyme with React 18. If you’re still using Enzyme, it is time to look into alternatives. The most popular option besides Enzyme seems to be React Testing Library. However, incorporating RTL requires a […]
In this blog, we’ve discussed measuring and improving our performance using the Lighthouse audits. Google continued by introducing new tools that emphasize performance. Some time ago, they introduced the Web Vitals standard. In this article, we go through it and provide examples of measuring the Web Vitals metrics with React. Introducing Web Vitals There are […]
We’ve learned how to use Redux Middleware to manage WebSockets in a recent article. We’ve also got to know the Redux Toolkit Query and how it can improve our code. Interestingly, we can also use RTK Query to deal with a WebSocket connection. This article teaches how to establish a WebSocket connection with RTK Query […]
The Redux team is working hard to create tools that are helpful in many real-life situations. For example, Redux Toolkit is a big step in simplifying how we write applications with Redux. Another helpful tool is the Redux Toolkit Query. Its primary sources of inspiration are the Apollo Client and React Query. The code we […]