As your project grows, it gets difficult to determine which code we have already tested and which haven't. At the same time, this need arises regularly. It usually happens when not all team members write tests not in a responsible way. In this case, the quality of the project may suffer.
But there is a solution. We can measure the code testability. In this lesson, we'll get acquainted with a metric that helps calculate the number of tests and the testing quality.
How test coverage works
Developers refer to the code coverage metric as code test coverage. We analyze it by test frameworks that consider the relationship of the lines involved in the tests to all lines of the source code. For example, if there's a conditional construction in the code not covered by tests, then all lines of code in this construction aren't covered.
In Pytest, it is simple to measure coverage. It is enough to install one dependency and run the tests with the right flag:
poetry add pytest-cov
