Writing complex UI and maintaining it can be hard. Writing tests help, but writing tests is also hard. Storybook can help with both, and provide auto documentation for your components.

We will discuss about the code coverage and the ways to improve it. Also, we'll see how to optimize your unit test cases and with JEST framework.

Are tests a chore, or do they help us move faster? Let’s examine what makes testing great and not so great. We’ll focus on test strategies that help us code with confidence and clarity, and where they can cost us time and energy. The secret to good testing lies in how it shapes our developer experience. Do our tests give us useful feedback in a timely manner? How quickly can we tell what is wrong when a test suite fails? Do they document our features and explain our past decisions? We’ll answer these questions with better tests that give us joy.