Test Debt
// Definition
Accumulated shortcuts in the test suite — flaky tests, missing coverage, slow feedback loops — that compound until every change is painful. A subset of technical debt, with the same dynamics: cheap to ignore, expensive to clear.
// Related terms
Technical Debt
The implicit cost of choosing a quick or expedient solution today over a more durable one. In testing, it accumulates as flaky tests, missing coverage, and brittle locators that slow every future change.
Flaky Test
A test that passes and fails intermittently without any code changes, often caused by timing issues, shared state, async race conditions, or external dependencies. The single largest source of CI noise.
Code Coverage
The percentage of source-code lines, branches, or statements executed during a test run. A useful but easy-to-game metric — high coverage doesn't guarantee good tests.