TDD in React Test driven development (TDD) is a tool for breaking down complex problems into more manageable chunks. This post will explore my journey of applying a TDD approach to website development using React, Jest, and the React Testing Library. In this experiment, I didn’t look at the browser for feedback at all. Instead I got all of my feedback from the automated tests. By focusing on the behavior of the components I’m building, I am able to get a working UI quickly and I’m able to change it’s behavior while still verifying its accuracy.

Why write unit tests? As developers, we want to write code that works and has as few bugs as possible. For example, when we write some production code we expect that given an input of abc the application will respond with 123. Writing and running automated tests can give developers a high level of confidence that their code does what it’s supposed to do. Unit tests isolate the system under test and throw a variety of scenarios in the system’s direction.