Test Coverage

Mutation Testing

Mutation Testing Score vs Code Coverage: Which Metric Actually Matters?

Code coverage tells you which lines executed during tests. Mutation score (MSI) tells you whether your tests would catch a change in behavior. These measure different things. Coverage is cheap and fast. Mutation testing is expensive and slow. The right answer is to use both — coverage as a floor that

PHP

PHP Test Coverage with Xdebug and PCOV: Complete Setup Guide

Code coverage is one of those metrics that developers either obsess over or dismiss entirely. The truth sits between those extremes: coverage data is genuinely useful for finding untested code paths, but a 90% coverage number tells you nothing about whether those tests are actually meaningful. Understanding what coverage measures