Audits .NET test mock usage by tracing each mock setup through the production code's execution path to find dead, unreachable, redundant, or replaceable mocks.
Stryker.NET
Use the open-source free `Stryker.NET` mutation testing tool for .NET. Use when a repo needs to measure whether tests actually catch faults, especially in critical libraries or domains. USE FOR: the repo uses or wants Stryker.NET; mutation testing is needed for high-risk code. DO NOT USE FOR: every PR path by default in a large repo; simple coverage collection. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Trigger On
- the repo uses or wants
Stryker.NET - mutation testing is needed for high-risk code
Workflow
- Run mutation testing on critical projects, not blindly on the whole mono-repo.
- Keep it out of the fastest PR path unless the repo explicitly accepts the runtime cost.
- Stabilize tests first; mutation testing amplifies flaky or slow suites.
Deliver
- explicit mutation-test scope
- reproducible Stryker commands
Validate
- the selected scope is affordable in CI
- mutation score is interpreted with test quality, not as a vanity number
Load References
Related skills
Detects duplicate boilerplate, copy-paste tests, and structural maintainability issues across .NET test suites.
ALWAYS USE whenever asked to write, add, or generate unit tests for existing code, including one helper, function, class, or missing regression case as well as project-wide suites.