React is a JavaScript library for developing applications and site UI. Developed by Facebook ; now Meta. Maintained by a very stable community of developers, it’s features are tailored especially to handle single page apps for Web pages and Mobile interface. Upon creation of ReactJS, REST API has been preferred for the fetching and storage of server information. Over time, GraphQL has become a much more enhanced competitor for the REST API, gaining more efficiency and less run time.

Applications built with ReactJS boast Speed and dynamic optimization. A reason for this is because it is a front-end framework, as well as Jest, its default testing library. However, when using package-runner tools like create-react-app, one important SEO activity will be lacking in the source code because the content of your page will be displayed in root div and projected through JavaScript. Using NextJS in this case is ideal as SEO crawlers don’t pick it up anything otherwise.

While there are a lot of ways to test React, the key takes on testing React and Next will be summarized in the following paragraphs. By the end of this article, there are links to where can be further enlightened by an array of articles, enough to elevate your skill set value beyond the average test run developer.

More often, a developer is met with the dilemma of not knowing what exactly to test. -How do I know what to test for?-

Knowing that a single mistype could ruin a whole block of code doesn’t help either. Every unit of the code will need to pass an automated testing as a part of the whole. Usually, a developer will receive a “Legacy code” which is to say the default code that comes without tests and they need to be tested freshly. Other times it is the developer who has to pull one out from his sleeves.

For any of the scenarios, you should consider building suitable test cases to check that all the input functions trigger the defined output, and make sure these functions happen

Differences in the various methods and tools of testing can influence choice of use, and also what you are looking for. Enzyme by Airbnb is less of a framework and more of a utility kit for React testing with focus on working of the inner components and what shows to the end user. It gives the testing team a good simulation and rendering advantage on the component trees. For component mounting, Shallow and Mount are the primary functions.

Jest is another popular JavaScript library, for unit test creation and running tests mainly adopted by default on React builds. Developed by Meta as well, the kit works perfectly with ReactJS on default.

With Jest, developers have the liberty to conjure test functions with nearly no configuration. There’s also the “Snapshot testing” that is used in verifying the result rendering component.

The component tree to be checked is captured by screenshot and analyzed in comparison to the standard that is passed as the minimum requirement.

Currently, NestJS is still arguably the fastest growing Node JS framework used for building scalable, more efficient server side systems that are fit to undergo unit tests. Using the same building blocks as Angular and React, it gives room for developers to work with some of the popular dev op modules, primarily nest-specific and with a very detailed documentation Containing examples, code sources, etc.

It improves the ease of integrating popular concepts like GraphQL, Caching, Validation, etc. and provides applications that can easily carry out automation tests. Built with TypeScript, the framework is flexible enough to be used interactively with other libraries. This gives a great deal of freedom to the developer especially on the integration of external modules.

As previously mentioned, it is more advisable to have more unit tests and less of the more complex whole, just enough not to miss out on any one. A larger allocation of the time should also be dedicated to the much more valued tests that deal with functions that retain users.

Quality outweighs quantity in this case, keep it simple. Avoid writing codes that will be impossible for you to maintain and probably need modification after implementation. Another hack to help with simplicity is the use of Typescript, which is not exactly used in the automation testing process but it can come in handy when writing codes and converting them from static to Javascript. The process may seem like it needs a lot of time but eventually comes to play in keeping the code full.