More Than Just a Percentage
Ensuring the reliability and stability of code is crucial in software development. The higher the level of test coverage, the lower the chance of hidden errors. But what exactly does this mean, and why is it so important to measure? In this article, we present the most important techniques, common challenges, and how TestNavigator can help with all of this.
What is Code Coverage and Why Is It Important to Measure It?
Code coverage shows what portions of the codebase are covered by tests and what percentage of changes compared to the previous version were affected. It also helps identify which areas haven’t been tested at all.
Regular test coverage measurement allows for continuous tracking of testing efficiency and helps reveal if a new development was left out of testing. TestNavigator is especially useful in this regard, as it measures the actual functionality covered by testers – not just the theoretical state in a development environment.
Another advantage is the identification of bugs before deployment, catching issues during testing rather than in production. This helps avoid emergency fixes and unexpected costs. Testing also becomes more targeted and transparent – revealing not just that tests ran, but whether they covered the application’s critical components.
Test coverage reports make the development process more transparent. At a glance, they show where gaps exist and which areas still require testing.
Most Common Measurement Techniques
Coverage can be measured at multiple levels, providing various perspectives on what parts of the software were actually tested. Line coverage shows what percentage of the code lines were executed during testing. For example, if a file contains 100 lines of code and 75 were executed at least once, line coverage is 75%.
Branch coverage checks that all possible paths in conditionals (e.g., both