Current State:

• Testing Excellence: 13.5/20 points (67.5%)
• We have 742 unit tests but no coverage or mutation testing tracking

Recommendations from pmat:

1. Install cargo-llvm-cov and aim for ≥85% line coverage
2. Install cargo-mutants and aim for ≥80% mutation score

Implementation Plan:

Phase 1: Coverage Analysis

• Install cargo-llvm-cov
• Generate initial coverage report
• Add coverage target to Makefile
• Identify coverage gaps
• Document coverage in CLAUDE.md

Phase 2: Coverage CI Integration

• Add coverage job to ci.yml workflow
• Upload coverage reports to Codecov/Coveralls
• Add coverage badge to README.md
• Set coverage threshold gate (≥85%)

Phase 3: Mutation Testing

• Install cargo-mutants
• Run initial mutation testing analysis
• Document mutation score baseline
• Add mutation testing to Makefile (optional/manual)
• Consider adding to CI (warning: slow, maybe weekly only)

Phase 4: Documentation

• Update CLAUDE.md with coverage commands
• Update CLAUDE.md with mutation testing commands
• Document how to interpret coverage/mutation reports

Expected Impact:

• Testing Excellence: 67.5% → >85%
• Rust Tooling & CI/CD: 40.4% → >50% (coverage CI integration)
• Overall Rust Project Score: Maintain A+ grade with higher confidence

Priority: High (quality assurance and confidence in test suite)
Effort: Medium (requires CI integration and analysis time)