Testing in Node.js

Testing is one of the most relevant practices these days; it has become much more popular in the last couple of decades than in the past. Today, we build complex software with many dependencies and requirements that evolve over time. I strongly believe that testing is key when you are learning a new language or tool because it will provide you with a security net that will allow you to take more risks and move faster without breaking the previous code.

In this chapter, we will dive into the importance of testing and how to choose the right type of testing for your application. You will write your first test, and then we will learn about creating test suites by grouping related tests, demonstrating both Node.js core testing and the Jest library.

Writing good tests is not easy, but by the end of this chapter, you will have a clear idea of what principles to follow every time and how you can use a testing coverage tool to extend and refactor your tests over time...