Testing is one of the most important phases of the development process. Whatever type of project you are working on, testing is key if you want to deliver applications with high quality and make your users happy.

Just imagine what would happen if your favorite taxi application makes your driver take you to the wrong place or the price of your trip is higher than it's supposed to be? This embarrassing bug will undoubtedly produce a series of catastrophic events that will damage the reputation of the application and, worse still, the company reputation.

Learning how to test our Aurelia applications and how to correctly apply the Test-Driven Development (TDD) approach will improve the quality of your applications, avoid embarrassing bugs, make your users happier, and make you a better developer. So, in this chapter, we will cover the following topics:

• Benefits of testing
• TDD
• Aurelia testing framework
• Practicing testing
• Debugging our code