Testing

Integration testing with Jest, supertest and an in-memory MongoDB — fast, isolated and offline.

The testing setup gives you real integration tests that run against an in-memory MongoDB, so they're fast, isolated and need no running database.

What's included#

• Jest — the test runner
• supertest — HTTP assertions against your Express app
• mongodb-memory-server — a throwaway MongoDB spun up per test run
• an example auth test suite to copy from

Running tests#

npm test                 # run the suite
npm run test:coverage    # with a coverage report

Writing a test#

import request from 'supertest';
import { app } from '@/server.js';
 
it('creates a product', async () => {
  const res = await request(app).post('/product').send({ name: 'Widget' });
  expect(res.status).toBe(201);
  expect(res.body.name).toBe('Widget');
});

TypeScript#

For TypeScript projects, tests run through @swc/jest for fast transpilation, with a moduleNameMapper that strips .js from imports so @/x.js resolves to the .ts source. You write import { x } from '@/x.js' everywhere and it just works in both runtime and tests.