Code-MCP

```typescript import { describe, it, expect, beforeEach, afterEach, vi } from "vitest"; import request from "supertest"; // ============================================ // Unit Test Examples // ============================================ // Math Utilities Tests describe("Math Utilities", () => { describe("add", () => { it("adds two positive numbers", () => { expect(add(2, 3)).toBe(5); }); it("adds negative numbers", () => { expect(add(-1, -1)).toBe(-2); }); it("handles zero", () => { expect(add(0, 5)).toBe(5); }); }); describe("divide", () => { it("divides two numbers", () => { expect(divide(10, 2)).toBe(5); }); it("throws error on division by zero", () => { expect(() => divide(10, 0)).toThrow("Cannot divide by zero"); }); }); }); // Async Function Tests describe("Async Operations", () => { it("fetches data successfully", async () => { const result = await fetchData("123"); expect(result).toHaveProperty("id", "123"); }); it("handles errors gracefully", async () => { await expect(fetchData("invalid")).rejects.toThrow("Not found"); }); }); // ============================================ // Mock Examples // ============================================ describe("User Service with Mocks", () => { const mockUserRepo = { findById: vi.fn(), create: vi.fn(), update: vi.fn(), delete: vi.fn(), }; beforeEach(() => { vi.clearAllMocks(); }); it("finds user by id", async () => { const mockUser = { id: 1, name: "John" }; mockUserRepo.findById.mockResolvedValue(mockUser); const userService = new UserService(mockUserRepo); const result = await userService.getUser(1); expect(mockUserRepo.findById).toHaveBeenCalledWith(1); expect(result).toEqual(mockUser); }); it("creates user with hashed password", async () => { const input = { email: "test@example.com", password: "secret123" }; mockUserRepo.create.mockResolvedValue({ id: 1, email: input.email }); const userService = new UserService(mockUserRepo); const result = await userService.createUser(input); expect(mockUserRepo.create).toHaveBeenCalled(); expect(result.email).toBe(input.email); expect(mockUserRepo.create.mock.calls[0][0].password).not.toBe( input.password, ); }); }); // ============================================ // Integration Test Examples // ============================================ describe("API Integration Tests", () => { let app: Express; beforeEach(async () => { app = createApp(); await setupTestDatabase(); }); afterEach(async () => { await cleanupTestDatabase(); }); describe("POST /api/users", () => { it("creates a new user", async () => { const response = await request(app) .post("/api/users") .send({ email: "new@example.com", name: "New User", password: "password123", }) .expect(201); expect(response.body.success).toBe(true); expect(response.body.data).toHaveProperty("id"); expect(response.body.data.email).toBe("new@example.com"); }); it("rejects duplicate email", async () => { // Create first user await request(app) .post("/api/users") .send({ email: "test@example.com", name: "Test", password: "pass" }); // Try to create duplicate const response = await request(app) .post("/api/users") .send({ email: "test@example.com", name: "Test2", password: "pass" }) .expect(400); expect(response.body.error).toContain("already exists"); }); it("validates required fields", async () => { const response = await request(app) .post("/api/users") .send({ email: "test@example.com" }) .expect(400); expect(response.body.error).toBeDefined(); }); }); describe("GET /api/users/:id", () => { it("returns user by id", async () => { const createRes = await request(app) .post("/api/users") .send({ email: "test@example.com", name: "Test", password: "pass" }); const response = await request(app) .get(`/api/users/${createRes.body.data.id}`) .expect(200); expect(response.body.data.email).toBe("test@example.com"); }); it("returns 404 for non-existent user", async () => { await request(app).get("/api/users/99999").expect(404); }); }); }); // ============================================ // E2E Test Examples // ============================================ describe("Authentication Flow E2E", () => { let app: Express; let authToken: string; beforeAll(async () => { app = createApp(); await setupTestDatabase(); }); afterAll(async () => { await cleanupTestDatabase(); }); it("registers a new user", async () => { const response = await request(app) .post("/api/auth/register") .send({ email: "e2e@example.com", name: "E2E User", password: "securePassword123", }) .expect(201); expect(response.body.user.email).toBe("e2e@example.com"); }); it("logs in with credentials", async () => { const response = await request(app) .post("/api/auth/login") .send({ email: "e2e@example.com", password: "securePassword123", }) .expect(200); expect(response.body.token).toBeDefined(); authToken = response.body.token; }); it("accesses protected route with token", async () => { const response = await request(app) .get("/api/profile") .set("Authorization", `Bearer ${authToken}`) .expect(200); expect(response.body.email).toBe("e2e@example.com"); }); it("rejects access without token", async () => { await request(app).get("/api/profile").expect(401); }); }); // ============================================ // Test Utilities // ============================================ export function createTestUser(overrides = {}) { return { email: `test-${Date.now()}@example.com`, name: "Test User", password: "testPassword123", ...overrides, }; } export async function authenticateAs( app: Express, role: "user" | "admin" = "user", ) { const user = createTestUser({ role }); await request(app).post("/api/auth/register").send(user); const response = await request(app) .post("/api/auth/login") .send({ email: user.email, password: user.password }); return response.body.token; } // Stubs for examples (would be real implementations) function add(a: number, b: number) { return a + b; } function divide(a: number, b: number) { if (b === 0) throw new Error("Cannot divide by zero"); return a / b; } async function fetchData(id: string) { if (id === "invalid") throw new Error("Not found"); return { id }; } class UserService { constructor(private repo: any) {} async getUser(id: number) { return this.repo.findById(id); } async createUser(data: any) { return this.repo.create({ ...data, password: "hashed" }); } } function createApp(): any { return {}; } async function setupTestDatabase() {} async function cleanupTestDatabase() {} type Express = any; ```