You are now just one step away from getting the maximum knowledge about full-stack applications and all the stuff it concerns. As we said earlier, one of the most important parts, and the one that makes the difference between just a programmer and a full-stack application developer, is testing. This chapter was meant to be easily understandable and highly applicable in your day-to-day work, giving you the most modern concepts and tools used in application testing.

You need to remember that integration tests are the assurance process of all components working well together, such third-party systems, external databases, and asynchronous processes. Depending on which platform you use, you will have a complete ecosystem to accomplish this and get the best value from your application. The best part is that you can automate all the tests at this layer and make your deployment process safer. One thing you cannot test using script is the usability of the application. You will need real humans to interact with your product and in this layer different UI testing techniques come to the rescue. Remember that user experience is one differential when you need to offer your products to the market.

Finally, all the different tests need to be documented to be used by other developers to improve more features of your application. Swagger is a very nice and simple tool to generate a detailed documentation and share with your team.

Now we have completely covered the testing phase! You know what time it is... Let's deploy! See you in the next chapter!