[sophielane]

Code coverage metrics are specific, quantifiable measures used to detail how a test suite exercises the source code, moving beyond the simple percentage of lines hit. These metrics provide a fine-grained view of testing thoroughness, allowing teams to identify and focus on different dimensions of risk within the codebase.
Key code coverage metrics include:

1. Statement Coverage (or Line Coverage): Measures whether each executable instruction or statement has been run at least once. This is the most basic metric.
   
2. Branch Coverage (or Decision Coverage): Ensures that every possible logical path in a control structure (e.g., both the
   TRUE
   and
   FALSE
   outcomes of an
   if
   statement) has been executed. This is significantly more rigorous than statement coverage.
   
3. Condition Coverage: Assesses whether every boolean sub-expression within a condition (e.g., in
   if (A AND B)
   ) has been evaluated to both
   TRUE
   and
   FALSE
   .
   
4. Function/Method Coverage: Determines if every function or method in the codebase has been called during the test run.
   

By analyzing multiple code coverage metrics, teams can build a comprehensive testing strategy that addresses not just what lines were run, but what logical paths and conditions were thoroughly validated, leading to a much higher degree of confidence in the final software product.