Code Coverage
Code coverage is a software testing metric that measures the percentage of source code executed during automated tests, indicating how thoroughly a codebase is tested. It helps identify untested parts of the code, such as statements, branches, functions, or lines, to improve test quality and reduce bugs. Tools like JaCoCo, Istanbul, and coverage.py generate coverage reports by instrumenting code or using runtime analysis.
Developers should use code coverage to ensure comprehensive testing, especially in critical applications like financial systems, healthcare software, or safety-critical systems where reliability is paramount. It helps prioritize test writing for uncovered code, supports refactoring by verifying existing functionality, and is often required in CI/CD pipelines to enforce quality gates before deployment.