Testing Testing Research v1.0.0

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.

Trigger On

  • the repo uses or wants Stryker.NET
  • mutation testing is needed for high-risk code

Workflow

  1. Run mutation testing on critical projects, not blindly on the whole mono-repo.
  2. Keep it out of the fastest PR path unless the repo explicitly accepts the runtime cost.
  3. 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

Reference data for .NET test framework detection patterns, assertion APIs, skip annotations, setup/teardown methods, and common test smell indicators across MSTest, xUnit, NUnit…

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.