Definition of Code coverage
Code coverage is a metric used in software development. You measure the extent to which the source code of your software has been tested by a corresponding set of tests. Code coverage expresses the ratio between tested and untested code.
Tracking code coverage helps you firstly to answer the question of whether you are testing enough. In addition, it also identifies the untested parts of your application.
But what does it mean to test your code? You verify whether it is semantically correct. In other words, does it behave as it should. Ultimately, this helps you assess the quality of your product or application.
What it says about quality
It is important to realize that code coverage tells you nothing about the quality of the performed tests. This means that code covered by tests is not automatically of high quality.
Therefore, be cautious about making a high percentage of coverage a goal in itself. Certainly, do not enforce it on others. here is a good chance that this leads to counterproductive behavior. Think, for example, of tests that do not check whether the behavior of the code is correct.
If you now have low code coverage, this most likely requires a different way of working for you and your team. Start by writing tests (before you write a line of code) and make this part of your daily routine. Identify high-risk areas in the code that are currently not covered and write tests for those areas. In this way, you will quickly reap benefits and achieve the real goal: effectively increasing the quality of your software.