Coverage Theater

ELI5 — The Vibe Check

Coverage theater is writing tests that hit every line of code but actually test nothing. Your coverage badge says 98%. Your production bugs say your tests are a lie. Assertions matter more than line counts.

Real Talk

Coverage theater is the anti-pattern of optimizing test suites for coverage percentage rather than defect detection. Symptoms include tests that execute code without assertions, tests that assert tautologies, and tests that mock everything meaningful. High coverage correlates poorly with defect prevention — assertion quality, mutation testing, and integration coverage are better signals.

When You'll Hear This

"99% coverage but prod broke three times this month — classic coverage theater." / "Mutation tests killed 40% of assertions. That's coverage theater."