minio-rs/.claude/commands/check-coverage.md

Check Test Coverage

Analyze code coverage for the MinIO Rust SDK and provide a detailed report.

Your Task

1. Install cargo-llvm-cov if needed

   • Check if llvm-cov is installed: cargo llvm-cov --version
   • If not installed: cargo install cargo-llvm-cov
   • This tool works well on Windows and all platforms

2. Run Coverage Analysis

   • First try: cargo llvm-cov --lib --tests (includes unit tests only)
   • Try to also include integration tests: cargo llvm-cov --all-targets --tests
   • For HTML report: cargo llvm-cov --lib --tests --html --output-dir target/coverage
   • For detailed output: cargo llvm-cov --lib --tests --text
   • Focus on library code, not test code itself
   • Important: Integration tests in tests/ directory may cover API functions and client operations

3. Parse and Present Results

   • Show overall coverage percentage (from both unit and integration tests)
   • List files with their coverage percentages
   • Identify files/functions with <100% coverage
   • Highlight critical uncovered code paths in src/madmin and src/s3
   • Separate coverage by module (madmin vs s3)
   • Note: Report which coverage comes from unit tests vs integration tests
   • Call out API/client methods that are covered by integration tests

4. Provide Actionable Report Present findings in this format:

   ## Coverage Summary
   - Overall: XX.XX% (from unit + integration tests combined)
   - Unit Test Coverage: XX.XX%
   - Integration Test Coverage: XX.XX%
   - Lines covered: XXXX / XXXX
   - Functions covered: XXX / XXX
   
   ### Module Breakdown
   - src/madmin: XX.XX% (XXXX/XXXX lines) [Unit XX% / Integration XX%]
   - src/s3: XX.XX% (XXXX/XXXX lines) [Unit XX% / Integration XX%]
   
   ## API/Client Methods Covered by Integration Tests
   - src/s3/client/put_object.rs - covered by integration tests
   - src/s3/response/list_objects.rs - covered by integration tests
   - [List all methods with integration test coverage]
   
   ## Files Below 100% Coverage
   
   ### MinIO Admin (madmin)
   #### src/madmin/builders/some_file.rs (XX.XX%)
   - Line 45-52: Error handling path not tested (both unit and integration)
   - Line 78: Builder method combination not covered
   
   #### src/madmin/response/other_file.rs (XX.XX%)
   - Line 23-25: JSON parsing error path missing test
   
   ### S3 API (s3)
   #### src/s3/client.rs (XX.XX%)
   - Line 123-130: Error handling for network failures
   - Line 245: Retry logic not tested
   
   #### src/s3/args/some_arg.rs (XX.XX%)
   - Line 67-70: Validation edge case
   
   ## Recommendations
   1. [madmin] Add test for error case in some_file.rs:45-52
   2. [madmin] Test builder method combinations in some_file.rs:78
   3. [s3] Add network failure test in client.rs:123-130
   4. [s3] Test validation edge case in args/some_arg.rs:67-70
   5. Investigate which integration tests are failing and fix them to improve coverage
   

5. Suggest Next Steps

   • Recommend which tests to write first (prioritize critical paths)
   • Indicate which API methods ARE covered by integration tests vs which are not
   • Note which integration tests are failing/skipped and why
   • Suggest whether to run /test-coverage to auto-generate tests for uncovered paths
   • Identify if any coverage gaps are in trivial code that can be ignored

Do not make any code changes - only analyze and report.