duroxide-code-coverage

Duroxide Code Coverage

Guidance for measuring and improving code coverage in the Duroxide codebase.

Quick Commands

# Summary (recommended for quick checks)
cargo llvm-cov nextest -p duroxide --all-features --summary-only

# Detailed per-file report
cargo llvm-cov nextest -p duroxide --all-features

# HTML report (opens in browser)
cargo llvm-cov nextest -p duroxide --all-features --html --open

# Install llvm-cov if needed
cargo install cargo-llvm-cov

Coverage Targets

Metric	Target	Notes
Lines	>90%	Primary metric
Regions	>85%	Branch coverage
Functions	>80%	Often lower due to unused helpers

Priority Files

When coverage drops, focus on these files:

1. src/providers/error.rs - Target 100%, error classification
2. src/runtime/observability.rs - Target 90%, metrics correctness
3. src/providers/sqlite.rs - Target 85%, reference implementation
4. src/providers/instrumented.rs - Target 75%, observability wrapper
5. src/providers/management.rs - Note: default trait impls inflate gaps

Adding Tests

Gap Type	Location
Management API	tests/coverage_improvement_tests.rs
Provider validation	tests/sqlite_provider_validations.rs
Observability	tests/observability_tests.rs
SQLite edge cases	src/providers/sqlite.rs (inline tests)

Test Patterns

Management API

#[tokio::test]
async fn test_management() {
    let store = Arc::new(SqliteProvider::new_in_memory().await.unwrap());
    let mgmt = store.as_management_capability().unwrap();
    assert!(mgmt.list_instances().await.is_ok());
}

Metrics

#[tokio::test]
async fn test_metrics() {
    use duroxide::runtime::observability::{MetricsProvider, ObservabilityConfig};
    let metrics = MetricsProvider::new(&ObservabilityConfig::default()).unwrap();
    metrics.record_orchestration_failure("Orch", "1.0", "app_error", "cat");
    assert_eq!(metrics.snapshot().orch_application_errors, 1);
}