Enzyme VS styled-components

Probably Enzyme was the first to popularize component testing in React by doing shallow rendering and expecting some things to be there in the React component tree. Then React Testing library came and took component testing to a whole new level.

Enzyme is another popular testing utility for React. It allows you to manipulate and traverse React components' output, making it easier to write comprehensive tests.

ljharb is an extremely interesting person. There’s no doubting the positive impact he’s had on the OSS community and the work he’s done.

However, there are some things he does that are incomprehensible.

For example, Enzyme. Over three years ago this issue was opened for Enzyme on React 17: https://github.com/enzymejs/enzyme/issues/2429

Nothing moved for a while, and I think he said something along the lines of “if you want React 17 support, stop complaining and help”. So the community got involved. There are multiple PRs adding React 17 support. Many unofficial React 17 adapters. A lot of people have put a lot of work into this, ensuring compatibility, coverage etc. Yet to this day, none of them have been merged. Eg https://github.com/enzymejs/enzyme/pull/2564

Given the amount of time that has passed, and the work the community has put in, something is amiss. It feels like he’s now intentionally avoiding React 17+ support. But why? I don’t understand why someone would ask for help then ignore the help when it comes in. That isn’t much better than the swathe of rude/entitled comments he was getting on the issue before he locked it.

I ended up migrating to RTL, but this made many of my tests more complicated (especially compared to shallow rendering).

Enzyme Documentation

One way to do this is by writing tests for your React components. Tools like Jest and Enzyme make it easy to test your component's behavior, rendering output, and state changes. By writing tests for your components, you can ensure that they behave as expected and prevent issues before they reach production.

GitHub link: https://github.com/enzymejs/enzyme

So If you have experience with enzyme testing, where you might be checking the value of state once you click any button or you might be checking the prop value If something changes.

Enzyme offers two types of API for shallow rendering and full rendering. Both are preferred for different test scenarios and functionalities.

At Visa, I was writing unit tests for a Next.js project using components designed with Chakra UI. That's where React Testing Library came in handy. Unlike other solutions like Enzyme, I did not have to worry about the application snapshot but could instead focus on each UI element, its expected behaviour and the data it would render upon user interactions.

Superset uses Jest and React Testing Library (RTL) to write unit and integration tests. In the past we used Enzyme, but now that we're currently converting all of our class components to functional components, Enzyme cannot support our testing needs. Since RTL is better for testing functional components, we're converting all of our test files to RTL. This can be quite a learning curve - I've gone through a lot of the process so I'd like to share what I've learned so far.

CSS-in-JS is a styling technique wherein CSS is composed using JavaScript instead of defined in external files. This method allows CSS to be scoped locally to components rather than globally, reducing the probability of style conflicts. Utilizing JavaScript also enables dynamic styling easily aligned with the component's state or props. Libraries like Styled Components and Emotion are popular choices in the React ecosystem for adopting this method.

In 2023, I had a chat with Max Stoiber, CEO of Stellate, on a podcast to learn about his early success on GitHub. His first open-source project, react-boilerplate/react-boilerplate, gained a whopping 10k stars in just one weekend after appearing on the homepage of Hacker News. This success led Max to drop out of university and create several other popular open-source projects, including styled-components. This library accelerates the process of building styles in React components.

Embracing the styled-components library allows developers to write actual CSS code to style their components. It utilizes tagged template literals to style components, enabling a seamless integration of styles within the component's JavaScript file. This approach eliminates the mapping between components and styles, thus enhancing developer productivity and component reusability.

styled-components: Allows for maintainable styling with CSS-in-JS. Learn more

Over the past few years, I've worked with React apps utilising various CSS-in-JS libraries, starting with styled-components, transitioning through emotion, Theme UI, and finally Stitches. I've also integrated MUI, Mantine, and Chakra in numerous client projects.

There are several alternatives to MUI. shadcn/ui is a modern alternative that is very popular. Ant Design is also a great alternative. Charkra UI can also be used as a UI Framework. Some people suggest just using styled components. Some use Tailwind CSS. Yet, for both styled components and Tailwind CSS, one still writes a lot of CSS. This might not provide the best developer experience compared to using a UI Framework, especially if we aim to avoid designing all the pages on the website.

Website: Styled Components

The project is build using several ready made components available within, Mantine. It’s a fully featured React components library. However some places still use some custom CSS-in-JS so we used some good ol’ styled components.