name: calculate-coverage description: "Measure test coverage and identify untested code. Use when assessing test completeness." mcp_fallback: none category: analysis tier: 2

Calculate Coverage

Measure code coverage percentage and identify which code paths are untested to ensure comprehensive testing.

When to Use

• Checking test coverage for modules
• Identifying gaps in test suites
• Meeting coverage thresholds (typically 80%+)
• Planning additional test cases

Quick Reference

# Python coverage with pytest
pip install coverage pytest-cov
pytest --cov=module_name --cov-report=html tests/

# View coverage report
open htmlcov/index.html

# Check coverage threshold
coverage report --fail-under=80

Workflow

1. Install coverage tool: Set up measurement infrastructure
2. Run tests with coverage: Execute test suite capturing coverage data
3. Generate report: Create HTML or text coverage report
4. Analyze gaps: Identify untested functions, branches, edge cases
5. Plan improvements: Create tests for uncovered code paths

Output Format

Coverage analysis:

• Overall coverage percentage
• Per-module coverage breakdown
• Uncovered lines (with line numbers)
• Branch coverage (if applicable)
• Recommendations for improvement

References

• See run-tests skill for test execution
• See generate-tests skill for test creation
• See CLAUDE.md > Key Development Principles (TDD) for testing strategy