Testing

NestJS facilita tests unitarios, de integracion y e2e con su testing module.

Test unitario

describe('ProductsService', () => {
  let service: ProductsService

  beforeEach(async () => {
    const module = await Test.createTestingModule({
      providers: [ProductsService, { provide: ProductsRepository, useValue: fakeRepo }],
    }).compile()

    service = module.get(ProductsService)
  })

  it('finds products', async () => {
    await expect(service.findAll()).resolves.toEqual([])
  })
})

Test e2e

const moduleFixture = await Test.createTestingModule({
  imports: [AppModule],
}).compile()

app = moduleFixture.createNestApplication()
await app.init()

Supertest

return request(app.getHttpServer())
  .get('/health')
  .expect(200)

Buenas practicas

• Unit tests para servicios.
• E2E para flujos HTTP.
• Mock de clientes externos.
• Base real con Testcontainers si el riesgo lo pide.
• Ejecutar tests en CI.