crap-analyzer

crap-analyzer

Claude Code plugin that analyzes recently-changed code for Change Risk Anti-Patterns (CRAP) and proposes fixes.

CRAP(m) = comp(m)² × (1 − cov(m))³ + comp(m)

High CRAP = complex and under-tested. This plugin flags the worst offenders in a diff, then offers refactors and test stubs one at a time.

What it does

1. Scopes to a diff. Any diff — gh pr diff, git diff --merge-base main, staged changes, or a named file list.
2. Auto-discovers coverage. Reads the repo's own coverage script (package.json, pyproject.toml, Makefile, etc.) or detects the framework (Jest, Vitest, pytest, JaCoCo, Go, RSpec, cargo-llvm-cov, coverlet, PHPUnit…). Parses lcov, Cobertura XML, JaCoCo XML, Clover XML, Go coverage.out, or coverage.py JSON.
3. Ranks findings worst-first with a markdown report.
4. Proposes fixes per finding: extract-method / guard-clause refactors as unified diffs, plus framework-appropriate test stubs.
5. Safe refactors (no behavior change) can be auto-applied one at a time after confirmation.

Supported languages

TypeScript, JavaScript, Python, Java, Kotlin, Go, Ruby, C#, Rust, PHP.

Usage

Trigger with any of:

• analyze CRAP
• check code risk on this branch
• run /crap-analyzer
• find risky methods in this PR

The plugin will prompt before running any tests or applying any edits.

Config

Optional .crap-analyzer.json at repo root:

{ "threshold": 20 }

Default threshold is 20 — functions below that score don't get reported.