Mastering Flask Web Development - Second Edition

What are unit tests?

Testing a program is very simple. All it involves is developing code that will run particular pieces of your program and specifying what you expect the results to be, and then comparing it to what the results from the piece of the program actually are. If the results are the same, the test passes. If the results are different, the test fails. Typically, these tests are run upon Pull Request creation on your CI server, so all the reviewers of the PR can immediately check if the requested change breaks something or not.

In program testing, there are three main types of tests. Unit tests are tests that verify the correctness of individual pieces of code, such as functions. Second is integration testing, which tests the ...