Write and run API tests with Vitest for endpoints, middleware, and integrations. Use when testing API functionality, request/response validation, error handling.
Use when invalid data causes failures deep in execution, requiring validation at multiple system layers - validates at every layer data passes through to make bugs structurally impossible
Use this agent when you need to validate code quality through testing, including running unit and integration tests, analyzing test coverage, validating error handling, checking performance requirements, or verifying build processes. This agent should be called after implementing new features or making significant code changes to ensure everything works as expected. Examples:\n\n<example>\nContext: The user has just finished implementing a new API endpoint and wants to ensure it works correctly.\nuser: "I've implemented the new user authentication endpoint"\nassistant: "Great! Now let me use the tester agent to run the test suite and validate the implementation"\n<commentary>\nSince new code has been written, use the Task tool to launch the tester agent to run tests and ensure everything works properly.\n</commentary>\n</example>\n\n<example>\nContext: The user wants to check test coverage after adding new features.\nuser: "Can you check if our test coverage is still above 80%?"\nassistant: "I'll use the tester agent to analyze the current test coverage and provide a detailed report"\n<commentary>\nThe user is asking about test coverage metrics, so use the tester agent to run coverage analysis.\n</commentary>\n</example>\n\n<example>\nContext: After fixing a bug, ensuring the fix doesn't break existing functionality.\nuser: "I've fixed the database connection issue in the auth module"\nassistant: "Let me use the tester agent to run the test suite and ensure the fix doesn't introduce any regressions"\n<commentary>\nAfter bug fixes, use the tester agent to validate that existing tests still pass.\n</commentary>\n</example>
Comprehensive testing strategies for Rust including property-based testing with proptest, fuzz testing with cargo-fuzz, benchmark testing with Criterion, contract testing for traits, and Miri for undefined behavior detection. Use when writing tests, ensuring code correctness, detecting edge cases, or measuring performance.
Synthesize all quality assessments (risk, test-design, traceability, NFR) into evidence-based gate decision (PASS/CONCERNS/FAIL/WAIVED) with comprehensive rationale. Generates both YAML (CI/CD) and Markdown (human review) reports with action items. Use during final quality review to make go/no-go deployment decisions based on comprehensive quality evidence.
Ensures all new screens/components have unit tests with proper coverage. Validates test files exist for loading, error, success, and state-transition states. Checks that backend handlers have corresponding test files. Use when creating or modifying frontend screens, components, or backend handlers.
Compare production WordPress sites against their baked static versions to find differences. Use when testing Bake deployments, checking for missing assets, broken styles, console errors, or any visual/functional discrepancies between production and static sites. Triggers on requests to compare sites, verify bake output, check for differences, or test static deployments.