After React-based apps are created, these apps need to be tested with different testing tools. You can check the react apps manually or through digital tools and codes. Either render the components separately or run the entire program in a browser-like environment while performing end-to-end testing. However, if you are going to run some automated tests, then React Testing Library is one such library that tests the complete React apps with its code.
What is React Testing Library?
By incorporating APIs into the format, the React testing library, which is a format of testing components developed on top of the DOM testing libraries, can be used to test React components. The React testing library is an essential tool as it is specifically designed for the components of React apps and complete algorithms.
Common Features of React Testing Library
Speed or real environment
The speed of the testing process and a quick feedback loop are very important features of the React Testing Library. The speed of testing can help get approval for a huge number of apps. The speed often lacks a proper browser environment that helps in app modeling. A realistic browser environment that helps in the proper integration of the app with the server is also needed.
A better testing solution than other libraries
Instead of interacting with instances of rendered React components, the app meets DOM elements thanks to the DOM testing process. The app is therefore tested in accurate test cases based on the objective C language. The algorithm of the React testing library allows the person to check for the queries of DOM in a user-friendly language.
Therefore, the final product that comes out is like a user command without the need for any hassle or unnecessary language. The data-tested escape route is also used by the React testing framework for elements where the label and text content are illegible. If the label and the text do not coincide, then the label does not work properly and needs to be gotten rid of.
The application testing library also offers the benefits of being more accessible and makes sure that the tested application is useful to the users.
Cheat code to a basic rendering test
The cheat code for the basic rendering test on the React Testing library is as follows-
If you take an App.js file and run it on the library, the React Testing Library has a render function that will take any kind of JSX code and render it. With this, you have access to the React component of the test. Then, the programmer can check for the library’s debug function. The command line will give you an output of the HTML code for the app.js file.
Running Queries in the React Testing Library
The running of queries can help you get the elements on the testing page. There are many types of queries like get, find, and query. After the element is found and isolated, you can then run the events API or user events to start the event and simulate user interactions. The query process also uses Jest and jest-dom to make assertions about the element.
How much to create and mock?
If you are going to test the individual components one by one, the difference between the unit testing and the integration test blurs out. It is possible to test the individual components with separate testing and to test the entire framework under integrative testing.
React testing library simplifies the testing process and is based on one guiding principle. The testing library works on the basis that the tests designed should also resemble the environment in which the app will finally work. The real-time environment will ensure you about the actual functionalities of the application.
Why then use the React Testing Library?
There are many testing libraries for programmers who work with the React Native code. Why is the React Testing Library the most useful one? Read on to find more-
The React Testing Library helps you test the components and the whole application so that there is an increase in the confidence behind the app. The app testing library has both unit and integration tests to ensure that all the apps are useful and properly created. The acting process of the React Testing Library does not focus on the component’s API but rather focuses on the text that comes out as a component function.
React Testing Library helps in creating tests that are well-designed and accurate. Instead of focusing on the implementation details, the React Testing library focuses on the components and complete applications.
The tests are on the React Testing Library, which works on complete speed and accuracy. The tests designed by React Testing Library help create very productive tests. Programmers can use the designed tests without much hassle or concern about accuracy.
The syntax of the React Testing Library is very intuitive and simple. The React Testing Library is easily used by programmers to create very accurate tests. The programmers can create more tests and gather more experience in writing tests.
The programmers do not have to go into the details of the test design because the test code is so intuitive. You can start querying the DOM with the help of getByText, and getByAltText processes.
Elements Of Query In React Testing Library
There are many types of queries, and they could be single or multiple types of questions.
Single Queries
getBy
The getBy query helps you find a matching node and throws a descriptive error code if the elements do not match. The getBy query is a very important query to run and find new codes.
QueryBy
The QueryBy code is run to find an element, and if there is no element match, then you get a nil code as a return. This query is run to ensure an element is present or not present.
findBy
findBy is a query that is run and returns with a promise which resolves when an element is found and it matches with the given query. If no element is found or more than one element is found, the Promise is invalid.
Multiple Elements queries
getAllBy
It returns an array of all the matching nodes to a query, and it throws an error if there are no elements to match. If there are no elements to find and match, the query fails.
queryAllBy
The queryAllBy command returns all the matching nodes to the query. However, if there are no matching nodes, it returns an empty array that does not work properly.
FindAllBy
The FindAllBy is a query that returns a promise resolved into an array of elements. Whenever elements are found that match the given query, it gets resolved. If there are no elements of the query, it is rejected.
Levels Of Component Tree To Test In React Testing Library
Many levels of the component tree can be tested with the React Testing Library. The React Testing Library is a testing algorithm that can test both the children and the parent of the component tree. However, if you are confused about different types of tests, look into user experience and test the components based on the user experience you want the component to serve.
Based on user experiences, you can break down the components and test them. The interactions the user has with the app and the functionalities of the app that it gathers from the components are all areas of use that should be tested. Based on the specific components you want to test, you can choose the testing procedure. The testing procedure can be used to test reusable components individually.
At other times, the specific breakdown of the component tree can be tested. The implementation details of the test are not so important for the React testing library. Sometimes, testing the individual components again and again can cause issues. Therefore, it is important to go higher up the component tree to simulate realistic user interactions.
Conclusion
The above are the queries and testing processes of basic code on the React Testing library. The accessibility, usability, and syntax of the React testing library are important aspects for programmers. Programmers are opting for the React Testing Library because it is easy to use, and the complete components of the app can be tested on it. There are other testing libraries for React native apps, but the React testing library is the best one. Whether you are a basic-level React developer or a high-level, experienced React developer, the React Testing Library is an important tool for you.
