Why `vitest --changed` misses some tests (and how runtime coverage fixes it) (opens in new tab)

Your CI re-runs the entire test suite on every push. But a one-line change can only break a handful of tests. The rest is wasted compute — and wasted minutes you spend waiting. The usual fix is "run only the tests affected by my change." Vitest and Jest ship this: vitest --changed jest --onlyChanged jest --findRelatedTests These are great. But they share a blind spot, and that blind spot can make them skip a test that your change actually breaks — the worst possible failure for a test...