Unit-testing React components

React is hinged on the component-driven development philosophy, and testing a unit of a React component further takes us closer to the basic elements that make up a React component. The essence of unit testing is to test an individual chunk of code to ascertain that the functionality works as expected by the users.

As stated earlier, in unit testing, you systematically go through three stages – planning, case scripting, and testing. Writing a unit test should be thoroughly planned, descriptive test cases should be implemented, and assertions should be clear enough to be understood by everyone on the team.

However, before we delve into unit-testing a React component, how do we know what to test in a React application? It is simple. Every React application has one or more components with specific functions. So, what to test in a React application is subjective. Every project is different and so is the functionality of the applications. The application...