Mojo Test Runner Skill

Execute Mojo tests with filtering and reporting.

When to Use

• Running Mojo test suites
• Verifying implementation correctness
• TDD red-green-refactor cycle
• Checking test coverage before PR

Quick Reference

# Run all tests
mojo test tests/

# Run specific file
mojo test tests/test_tensor.mojo

# Run with verbose output
mojo test -v tests/

# Run tests matching pattern
./scripts/run_tests.sh tensor

Workflow

1. Run tests - Execute mojo test or script
2. Review output - Check pass/fail summary
3. Fix failures - Address failing tests
4. Re-run tests - Verify all pass

Mojo-Specific Notes

• Test functions must start with test_
• Test files must match test_*.mojo or *_test.mojo
• Tests run independently - no shared state between tests
• Use raises keyword for exception testing

Error Handling

| Error | Cause | Solution | |-------|-------|----------| | Import error | Module not found | Verify -I include paths | | Syntax error | Invalid test code | Fix syntax before testing | | Timeout | Test too slow | Optimize or increase timeout | | Memory error | Ownership issue | Check ownership and borrowing |

References

• .claude/shared/mojo-anti-patterns.md - Common test mistakes
• /notes/review/ - Testing strategy documentation