It also covers coverage thresholds, deterministic test isolation, and the rule to never mix bun:test and vitest imports in one package, or run bun test when the configured runner is actually Vitest.

Out of scope: framework-specific testing (React components → react-expert's react-testing, Laravel → laravel-testing) and browser E2E suites are not covered.

TypeScript Testing

Pick the right runner, then write tests with a shared Jest-compatible API.

Agent Workflow (MANDATORY)