Coverage Tooling

This project uses cargo-llvm-cov for code coverage analysis with a >80% coverage threshold.

Setup

Install the coverage tooling dependencies:

just setup

This will install:

• rustfmt and clippy components
• cargo-llvm-cov for coverage analysis

Running Coverage

Local Development

# Generate coverage report with 80% threshold
just coverage

# Generate HTML coverage report for local viewing
just coverage-html

# View coverage report in terminal
just coverage-report

The HTML report will be available at target/llvm-cov/html/index.html after running just coverage-html.

CI/CD

The CI system automatically runs coverage analysis:

# CI-friendly coverage (ignores test failures but still generates coverage)
just coverage-ci

Coverage Files

• lcov.info - Coverage data in LCOV format (uploaded to Codecov)
• target/llvm-cov/html/ - HTML coverage reports
• Coverage artifacts are excluded from version control via .gitignore

Coverage Configuration

Included in Coverage

• Library code (src/lib.rs and modules)
• Integration tests (tests/)
• Unit tests (within modules)
• Doctests (documentation examples)

Excluded from Coverage

• Benchmarks (benches/) - Automatically excluded as separate targets
• Generated files
• Test utilities (helper code in tests/common/)

Thresholds

• Line Coverage: >80% required (enforced by --fail-under-lines 80)
• Coverage failures will cause CI builds to fail
• Use just coverage-ci for CI environments to generate reports even with test failures

Troubleshooting

Coverage Too Low

If coverage drops below 80%:

1. Add more unit tests for uncovered code
2. Add integration tests for user-facing functionality
3. Add doctests for public APIs
4. Remove dead/unreachable code

View Missing Coverage

just coverage-html
# Open target/llvm-cov/html/index.html in browser

The HTML report shows exactly which lines are not covered.

Clean Coverage Data

just coverage-clean

Commands Reference