crap-score

Run dotnet test with coverage collection to produce a Cobertura XML report, then compute cyclomatic complexity by counting decision points in the method. Apply the formula CRAP = complexity² × (1 - coverage)³ + complexity using the method's line-rate from the coverage data.

A CRAP score below 5 indicates simple, well-tested code, while 5-15 is acceptable for most methods. Scores of 15-30 are high risk needing more tests or simplification, and anything above 30 is critical and should be refactored and covered urgently.

The analysis works with Cobertura XML output from coverlet.collector via dotnet test --collect:"XPlat Code Coverage", or from Microsoft.Testing.Extensions.CodeCoverage on .NET 9 and later using the --coverage-output-format cobertura option.

Cobertura XML may use compiler-generated names for async methods, lambdas, and local functions, causing mismatches with source names. Match methods by line ranges instead of names when the identifiers do not align.

Avoid CRAP analysis for project-wide coverage diagnosis, coverage plateau investigation, or deciding where to add tests across an entire solution. It is designed for targeted assessment of a named method, class, or file, not broad coverage planning.

No. When cyclomatic complexity is 15 or higher, the minimum possible CRAP score equals the complexity itself, so coverage alone cannot bring it below the threshold. The method must first be refactored, for example by extracting sub-methods, to reduce complexity.