qa-backend-mean

name	qa-backend-mean
description	Backend testing for MEAN stack apps. Use when writing and running tests for Express API endpoints, MongoDB operations, authentication flows, and middleware using Jest and Supertest.

Qa Backend Mean

Purpose

Write and run backend tests for MEAN stack applications. Cover API endpoint testing with Supertest, MongoDB operation testing with in-memory database, authentication flow testing, middleware testing, and integration testing.

Key Patterns

Test Structure

• server/tests/setup.js — Global test setup (DB connection, cleanup)
• server/tests/fixtures/ — Test data factories
• server/tests/integration/ — API endpoint tests
• server/tests/unit/models/ — Model and utility tests
• server/tests/middleware/ — Middleware tests

Test Setup (MongoDB Memory Server)

• Use MongoMemoryServer for isolated test database
• beforeAll: create memory server, connect mongoose
• afterAll: disconnect, stop server
• afterEach: clear all collections (full isolation between tests)
• Set NODE_ENV=test and JWT_SECRET=test-secret

Integration Test Pattern (Supertest)

• Import app (not listening server) from server.js
• Use request(app).get/post/put/delete to test endpoints
• Chain .send() for body, .set() for headers, .expect() for status
• Assert: response status, body shape, key field values, side effects (DB state)

Fixture Factory Pattern

• Default valid data objects for each model
• createX() function that saves to DB and returns document
• getAuthToken() helper: creates user + signs JWT, returns { user, token }
• Override defaults with spread: createUser({ role: 'admin' })

Auth Testing Pattern

• Test register: success (201), duplicate email (409), validation errors (422)
• Test login: success (200 + token), wrong password (401), non-existent user (404)
• Test protected routes: with valid token (200), without token (401), with invalid token (401)
• Test role-based: authorized role (200), unauthorized role (403)

Conventions

• Jest as test runner with --detectOpenHandles --forceExit flags
• mongodb-memory-server for isolated test DB — NEVER test against real database
• Supertest for HTTP integration tests — test full request/response cycle
• Test file naming: {name}.test.js
• Each test file: describe block per endpoint, it blocks per scenario
• Test happy path first, then error cases, then edge cases
• Coverage: aim for 80%+ on controllers and middleware, 100% on auth flow
• Export app (not listening server) from server.js for Supertest

Knowledge Strategy

• Patterns to capture: Test patterns for common MEAN features (CRUD, auth, file upload, pagination)
• Examples to collect: Complete test files for standard endpoints, fixture factories
• Update permission: Agents may freely add/update files in references/. Changes to SKILL.md or scripts/ require user approval.