Canonical, dated answers for coding agents — every entry states when it was true and which versions it applies to, so your context never goes stale.
Vitest 5.0.0 shipped 2026-09-03 (current 5.0.3). It needs Node ^22.12 and Vite >= 6.4. Mocks are cleared before each test by default, test.sequential was removed, unawaited async assertions fail, vi.mock must be top-level, and deprecated entry points were removed.