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Verification · Testing

Mutation testing

Changes the code on purpose and checks that some test fails; surviving mutants show tests that do not constrain behaviour.

Sub-techniques

Diff-scoped mutation V1023.001

Mutate only lines changed in the PR to keep runtime bounded.
Mutation score gate V1023.002

Fail when the score on changed code drops below a threshold.

How to build it

Run on one critical module first to see the runtime.
Scope to changed lines on PRs.
Treat each surviving mutant as a missing assertion, not a number to optimise.

Signals in a repository

stryker.conf, mutmut config or cargo-mutants in CI.
Mutation reports uploaded as artifacts.