name: testing description: > Testing conventions and patterns for the Agent Router project. Use when writing tests, creating test files, mocking dependencies, running vitest, or deciding what to test. Triggers on: test files, describe/it blocks, vitest commands, test coverage, mocking DB/Redis/LLM.

Testing Skill

Setup

•Vitest 4.x with global test APIs (describe, it, expect -- no import needed)
•Config: vitest.config.ts with @/ path alias
•Tests in tests/ at project root (not co-located)
•CI: lint -> type check -> npx vitest run --passWithNoTests (all must pass for PR merge)

Writing Tests

•Files: {module-name}.test.ts
•Structure: arrange / act / assert
•One behavior per it block
•Mock external deps (DB, Redis, LLM) -- no real service calls
•Test edge cases: empty inputs, boundary values, error conditions

What to Test

Aggregator, rate limiter, circuit breaker, redactor, Zod schemas, query builders

What NOT to Test

Next.js page rendering, tRPC route wiring, third-party internals

Commands

bash

npx vitest run              # Run all tests once
npx vitest run tests/foo    # Run specific test file
npx vitest                  # Watch mode