Who is testing your tests?
summary
Code coverage shows 100% code coverage but misses missing assertions and off-by-one property tests; mutation testing inserts tiny code changes and runs tests against each mutant. Running Stryker4s on a small library produces 150 mutants, takes ~37 seconds and yields a mutation score 68%, revealing survived mutants like changed comparisons and swapped forall/exists. Stryker4s uses mutation switching to compile once and toggle mutants, trading accuracy for practical speed.
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chapters (10)
- 0:00Start
- 4:51Property Testing
- 6:13Mutation Testing
- 9:55The Mutation Testing Tool
- 10:32Demo
- 11:21Code Coverage
- 13:56Mutation Score of 68
- 14:54Syntax Highlighting
- 17:00Developing a Mutation Testing Framework
- 20:29Mutation Switching
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