Instruction file imported from DHutchinson1991/ProjectFlo (.github/instructions/testing.instructions.md). Copyright stays with the author.

ProjectFlo — Testing Conventions

Backend (Jest + NestJS)

File naming & placement

• Co-locate tests with source: feature.service.spec.ts next to feature.service.ts.
• Suffix: .spec.ts for unit tests, .e2e-spec.ts for end-to-end.
• One spec file per source file. Name matches: quotes.service.ts → quotes.service.spec.ts.

Test structure

describe('FeatureService', () => {
  let service: FeatureService;
  let prisma: DeepMockProxy<PrismaClient>;

  beforeEach(async () => {
    const module = await Test.createTestingModule({
      providers: [FeatureService, { provide: PrismaService, useValue: buildPrisma() }],
    }).compile();
    service = module.get(FeatureService);
    prisma = module.get(PrismaService);
  });

  describe('create', () => {
    it('should create and return the entity', async () => { /* ... */ });
    it('should throw NotFoundException when parent missing', async () => { /* ... */ });
  });
});

Mocking

• Use buildPrisma() / buildPrismaTx() helpers from test utilities for Prisma mocks.
• Mock only direct dependencies — do not mock internals of the class under test.
• For transactions: mock prisma.$transaction to invoke the callback with a mock tx client.

What to test

Assertions

• Test both happy path and error paths (throw NotFoundException, BadRequestException).
• Use toEqual for object shape, toHaveBeenCalledWith for verifying service calls.
• Avoid snapshot tests for dynamic data.

Frontend

No frontend test framework is currently configured. When frontend tests are added, follow:

• Framework: Jest + React Testing Library.
• Files: ComponentName.test.tsx co-located with component.
• Focus on user interaction and rendered output, not implementation details.

Running tests

# From root
pnpm test

# Backend only (from packages/backend)
npm test
npm run test:e2e

# Single file
npm test -- --testPathPattern="quotes.service"