What problem does it solve? Writing unit tests for TypeScript backends often leads to inconsistent tooling choices and heavy dependencies on external frameworks like Jest or Vitest. This Skill enforces a strict, dependency-free testing approach using only the Node.js built-in test runner, producing isolated and readable tests. ## Core Features & Use Cases - Native Test Generation: Creates complete test files using node:test and node:assert/strict with AAA (Arrange, Act, Assert) structure. - Strict Dependency Isolation: Mocks repositories and external services using the native mock.fn() and mock.method() APIs, never touching databases, filesystems, or external APIs. - Design Feedback: Detects hard-to-test code such as temporal coupling (new Date()) or static calls and suggests dependency injection improvements. - Use Case: Ask for unit tests for a TypeScript service class, and receive a scenario list, a mock isolation strategy, and a complete runnable test file with no external test dependencies. ## Quick Start Ask the assistant to create unit tests for your TypeScript service class using only the native Node.js test runner and assert module.
