The Complete Production SOP: How to Deploy and Run Vitest & Jest High-Speed Unit Tester in Autonomous AI Agents

---
name: "vitest-unit-master"
description: "Author comprehensive unit tests, mock network calls via MSW, and enforce 90%+ code coverage."
dependencies:
  npm:
    - "vitest"
    - "@testing-library/react"
    - "msw"
---

# Vitest & Jest High-Speed Unit Tester SOP

1. Always mock HTTP/gRPC boundaries using Mock Service Worker (MSW v2) handlers; do not mock native `fetch` directly.
2. Query DOM nodes via `@testing-library/react` using accessible queries (`getByRole`, `findByText`). Never use direct DOM traversal.
3. Enforce isolated runtime states: call `server.resetHandlers()` and `vi.clearAllMocks()` in `afterEach` hooks.
4. Execute `vitest run --coverage` and verify overall branch, function, and line coverage meets >= 90% before completion.

import '@testing-library/jest-dom/vitest';
import { beforeAll, afterEach, afterAll } from 'vitest';
import { setupServer } from 'msw/node';

export const server = setupServer();

beforeAll(() => server.listen({ onUnhandledRequest: 'error' }));
afterEach(() => server.resetHandlers());
afterAll(() => server.close());

{
  "scripts": {
    "test:unit": "vitest run",
    "test:coverage": "vitest run --coverage --coverage.thresholds.100=false --coverage.thresholds.lines=90"
  }
}