How do automated tests work?

With automated tests, the pipeline is not tested manually anymore. Instead, test code is written, which runs various actions and compares the results to expected values. One button is pressed, and the complete code of the pipeline gets checked if it’s still working correctly. Imagine a robot clicking through the tools automatically and checking the results.

In reality, this is only one way how to do automated tests. It’s called UI Test. We will learn more about this in the section Test Pyramid. But most tests don’t rely on the UI; they operate at the code level and test individual units like methods or classes. We will learn more about that in the next chapter.