feat(tests): Jest backend (38 tests), Jest RTL frontend (28 tests), Playwright E2E spec

backend/tests/experiments.test.js

@@ -0,0 +1,138 @@
+const request = require('supertest');
+
+// Mock Prisma before importing app so the app uses the mock
+jest.mock('../src/lib/prisma', () => require('./__mocks__/prisma'));
+const prisma = require('../src/lib/prisma');
+const app = require('../src/app');
+
+const EXPERIMENT = {
+  id: 'aaaaaaaa-0000-0000-0000-000000000001',
+  title: 'Test Study',
+  created_at: new Date('2024-01-01').toISOString(),
+  _count: { animals: 0 },
+};
+
+beforeEach(() => {
+  jest.clearAllMocks();
+});
+
+describe('GET /api/experiments', () => {
+  it('returns list of experiments', async () => {
+    prisma.experiment.findMany.mockResolvedValue([EXPERIMENT]);
+    const res = await request(app).get('/api/experiments');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(1);
+    expect(res.body[0].title).toBe('Test Study');
+  });
+
+  it('returns empty array when no experiments', async () => {
+    prisma.experiment.findMany.mockResolvedValue([]);
+    const res = await request(app).get('/api/experiments');
+    expect(res.status).toBe(200);
+    expect(res.body).toEqual([]);
+  });
+});
+
+describe('GET /api/experiments/:id', () => {
+  it('returns single experiment', async () => {
+    prisma.experiment.findUnique.mockResolvedValue({ ...EXPERIMENT, animals: [] });
+    const res = await request(app).get(`/api/experiments/${EXPERIMENT.id}`);
+    expect(res.status).toBe(200);
+    expect(res.body.id).toBe(EXPERIMENT.id);
+  });
+
+  it('returns 404 for unknown id', async () => {
+    prisma.experiment.findUnique.mockResolvedValue(null);
+    const res = await request(app).get('/api/experiments/00000000-0000-0000-0000-000000000000');
+    expect(res.status).toBe(404);
+    expect(res.body.error).toMatch(/not found/i);
+  });
+});
+
+describe('POST /api/experiments', () => {
+  it('creates experiment and returns 201 with UUID', async () => {
+    prisma.experiment.create.mockResolvedValue(EXPERIMENT);
+    prisma.auditLog.create.mockResolvedValue({});
+
+    const res = await request(app)
+      .post('/api/experiments')
+      .send({ title: 'Test Study' });
+
+    expect(res.status).toBe(201);
+    expect(res.body.id).toBe(EXPERIMENT.id);
+    expect(res.body.title).toBe('Test Study');
+    // UUID format assertion
+    expect(res.body.id).toMatch(
+      /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
+    );
+    expect(prisma.auditLog.create).toHaveBeenCalledWith(
+      expect.objectContaining({ data: expect.objectContaining({ action: 'CREATE' }) })
+    );
+  });
+
+  it('returns 422 when title is missing', async () => {
+    const res = await request(app).post('/api/experiments').send({});
+    expect(res.status).toBe(422);
+    expect(res.body.details).toEqual(
+      expect.arrayContaining([expect.objectContaining({ field: 'title' })])
+    );
+  });
+
+  it('returns 422 when title exceeds 255 chars', async () => {
+    const res = await request(app)
+      .post('/api/experiments')
+      .send({ title: 'x'.repeat(256) });
+    expect(res.status).toBe(422);
+  });
+});
+
+describe('PUT /api/experiments/:id', () => {
+  it('updates experiment and writes audit log', async () => {
+    const updated = { ...EXPERIMENT, title: 'Renamed Study' };
+    prisma.experiment.findUnique
+      .mockResolvedValueOnce(EXPERIMENT)   // audit middleware fetches before-state
+      .mockResolvedValueOnce(updated);     // audit middleware fetches after-state
+    prisma.experiment.update.mockResolvedValue(updated);
+    prisma.auditLog.create.mockResolvedValue({});
+
+    const res = await request(app)
+      .put(`/api/experiments/${EXPERIMENT.id}`)
+      .send({ title: 'Renamed Study' });
+
+    expect(res.status).toBe(200);
+    expect(res.body.title).toBe('Renamed Study');
+    expect(prisma.auditLog.create).toHaveBeenCalledWith(
+      expect.objectContaining({ data: expect.objectContaining({ action: 'UPDATE' }) })
+    );
+  });
+
+  it('returns 422 with empty title', async () => {
+    prisma.experiment.findUnique.mockResolvedValue(EXPERIMENT);
+    const res = await request(app)
+      .put(`/api/experiments/${EXPERIMENT.id}`)
+      .send({ title: '' });
+    expect(res.status).toBe(422);
+  });
+});
+
+describe('DELETE /api/experiments/:id', () => {
+  it('deletes experiment and writes DELETE audit log', async () => {
+    prisma.experiment.findUnique.mockResolvedValue(EXPERIMENT);
+    prisma.experiment.delete.mockResolvedValue(EXPERIMENT);
+    prisma.auditLog.create.mockResolvedValue({});
+
+    const res = await request(app).delete(`/api/experiments/${EXPERIMENT.id}`);
+    expect(res.status).toBe(204);
+    expect(prisma.auditLog.create).toHaveBeenCalledWith(
+      expect.objectContaining({ data: expect.objectContaining({ action: 'DELETE' }) })
+    );
+  });
+});
+
+describe('GET /health', () => {
+  it('returns ok status', async () => {
+    const res = await request(app).get('/health');
+    expect(res.status).toBe(200);
+    expect(res.body.status).toBe('ok');
+  });
+});