Mutation testing: better code by making bugs
summary
Mutation testing is automated fault injection for tests using Infection with PHPUnit and Xdebug applied to a real Symfony dependency-injection repo. It generates 3,500 mutants (naïvely leading to 2.5 million tests), uses optimizations (skip non-covered code, parallel processes, mutator profiles) and drops run time to 10 minutes vs 53 hours. It surfaces weak or redundant tests, yields ~30% equivalent/useless mutants, and needs isolated CI (Docker recommended) to avoid side effects.
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chapters (10)
- 0:00Start
- 1:58Software Quality
- 6:26Cost of the Bugs
- 11:39How Do You Assess the Quality of Your Tests
- 13:31How Do You Assess the Quality of the Test Suit
- 14:36Code Coverage
- 18:31The Mutation Testing Tool
- 29:16Optimization Strategies
- 34:54Side Effects
- 35:09False Consequences
