Vitest Best Practices Vitest 5-compatible testing guide with 46 rules across 8 categories. Vitest 5 requires Node.js 22.12+ and Vite 6.4+; Vitest 4.1 remains on backport support. When to Apply Reference these guidelines when: - Writing new Vitest tests - Debugging flaky or slow tests - Setting up test configuration - Reviewing test code in PRs - Migrating from Jest to Vitest - Optimizing CI/CD test performance Jest-specific APIs and configuration outside documented migration differences are out of scope; use Jest's own documentation for tests that still run under Jest. Rule Categories by Prio…