Test Gap Analysis via Pseudo-Mutation

Analyze .NET production code by reasoning about hypothetical mutations and checking whether existing tests would catch them. This reveals blind spots where tests pass but would continue to pass even if the code were broken.

Why Pseudo-Mutation Matters

Code coverage tells you what code ran during tests. It does not tell you whether tests would fail if that code were wrong. A method can have 100% line coverage but zero tests that would catch a sign flip, an off-by-one error, or a removed null check.

Pseudo-mutation analysis asks: "If I changed this line, would any test fail?" When the answer is "no," you've found a test gap.

This skill performs static pseudo-mutation — reasoning about mutations without actually running them — to approximate mutation testing at the speed of code review.

When to Use