Accelint Ts Testing

Opinionated vitest testing guidance for TypeScript projects that emphasizes what not to do. The skill covers test organization using the AAA pattern, property-based testing with fast-check for roundtrip and idempotence checks, and a test doubles hierarchy (fakes over stubs over mocks). It's notably strict about avoiding loose assertions like toBeTruthy, never mocking your own pure functions, and never testing constants files or library internals. Includes a mandatory type checking step before marking tests complete. Most useful when you're trying to prevent brittle tests or optimize slow suites, though the prescriptive tone won't be for everyone. Worth reviewing if your team keeps hitting flaky test issues.