Coverage Reporter Skill

Comprehensive test coverage analysis and reporting for Python and TypeScript code.

When This Skill Activates

After running test suite
Before committing changes
Tracking coverage over time
Investigating coverage gaps
Reporting on coverage metrics

Coverage Analysis Methodology

Phase 1: Coverage Collection

Python Coverage

cd backend
pytest --cov=app --cov-report=html --cov-report=term-missing

TypeScript Coverage

cd frontend
npm run test:coverage

Phase 2: Gap Analysis

Step 2.1: Identify Untested Code

For each file:
1. Count lines not covered
2. Identify untested functions
3. Identify untested branches
4. Calculate coverage percentage

Step 2.2: Prioritize by Risk | Risk Level | Type | Priority | |-----------|------|----------| | Critical | Auth, crypto, data access | Fix immediately | | High | Business logic, validation | Fix within 48h | | Medium | Utils, helpers | Fix within 1 week | | Low | Formatting, display | Nice to have |

Phase 3: Coverage Report Generation

## Test Coverage Report

**Date:** [DATE]
**Overall Coverage:** [X]%

### Summary
- Backend: [X]%
- Frontend: [Y]%
- Target: 80%

### Critical Gaps
- [File]: [X]% - [reason]
- [File]: [Y]% - [reason]

### Trends
- Week 1: 75%
- Week 2: 77%
- Week 3: 79%
- Trend: Improving

### Recommendations
1. [Recommendation 1]
2. [Recommendation 2]

Phase 4: Trend Analysis

1. Historical coverage
   - Track weekly/monthly trends
   - Identify degradation
   - Project future coverage

2. Coverage velocity
   - How fast is coverage improving?
   - Estimate time to target

3. Coverage stability
   - Which areas consistently low?
   - Which areas consistently high?

Coverage Requirements by Layer

| Layer | Target | Minimum | |-------|--------|---------| | Services | 90% | 80% | | Controllers | 85% | 75% | | Models | 80% | 70% | | Utils | 90% | 85% | | Routes | 75% | 65% | | Components (Frontend) | 80% | 70% |

Quick Coverage Commands

# Python coverage with details
cd backend
pytest --cov=app --cov-report=html --cov-report=term-missing -v

# Frontend coverage
cd frontend
npm run test:coverage

# Coverage diff against main
# (Identify what new code is untested)
git diff main...HEAD | grep "^+" | wc -l

Gap Remediation Workflow

For Each Untested Component:

1. Understand the code
   - What does it do?
   - When is it called?
   - Why isn't it tested?

2. Determine test strategy
   - Unit test?
   - Integration test?
   - E2E test?

3. Write tests
   - Happy path
   - Error cases
   - Edge cases

4. Verify coverage
   - Re-run coverage
   - Confirm improved

Integration with test-writer

When coverage gaps identified:

Report findings to test-writer skill
Request test generation for gaps
Re-run coverage after tests added
Track improvement

Validation Checklist

[ ] Coverage >= target percentage
[ ] No untested critical code
[ ] All public APIs covered
[ ] Error paths tested
[ ] Edge cases covered
[ ] Coverage trend is improving
[ ] No artificial coverage inflation

References

Coverage requirements in CLAUDE.md
See test-writer skill for test generation
Testing patterns in python-testing-patterns skill