macalbert/envilder/code-quality-crap

Code Quality: CRAP Score

CRAP (Change Risk Anti-Patterns) measures the risk of a method based on cyclomatic complexity and test coverage.

When to Use

• Reviewing new or changed methods for complexity risk
• Deciding whether a method needs splitting
• Interpreting coverage risk for a given complexity
• During PURE_REFACTOR implementation or candidate review

Formula

$$\text{CRAP}(m) = \text{comp}(m)^2 \times (1 - \text{cov}(m))^3 + \text{comp}(m)$$

Where:

• $\text{comp}(m)$ = cyclomatic complexity of method $m$
• $\text{cov}(m)$ = test coverage ratio (0 to 1) of method $m$

Quality Gate

Every method MUST have a CRAP score below 6.

Coverage Thresholds

These thresholds are intentionally stricter than the mathematical minimum, providing a safety margin:

Actions by Scenario

Severity Classification

• Medium: complexity 4–5 without proportional test coverage
• High: complexity 6+ (must split, no amount of testing fixes it)