Test Rot
ELI5 — The Vibe Check
Test rot is when your test suite slowly becomes useless. Tests that never fail. Tests that test nothing. Tests that fail for unrelated reasons. The suite still runs green, but nobody trusts it.
Real Talk
Test rot is the degradation of a test suite's signal value over time: increasing flakiness, tautological assertions, obsolete mocks, and tests coupled to implementation details rather than behavior. Symptoms include tests that are 'skip-worthy' and high rerun rates. Prevention: treat tests as production code and refactor regularly.
When You'll Hear This
"Test rot is why nobody trusts green CI anymore." / "This suite has serious test rot — time for an audit."
Related Terms
Flaky Test
A flaky test is a test that sometimes passes and sometimes fails for no clear reason — even when nothing changed.
Technical Debt
Technical debt is the coding equivalent of putting things on a credit card.
Test Theater
Test theater is writing tests primarily to make reviewers happy rather than to catch bugs. The tests exist. They pass.