testing

测试规则（2026 年版）

补充人：墨铃 (Mori)
补充日期：2026-02-28
参考章节：第八章

---

单元测试

• 每个函数/模块必须有单元测试
• 覆盖率目标：≥ 80%（核心模块 ≥ 90%）
• 测试命名：should [预期行为] when [条件]
• 使用 Arrange-Act-Assert (AAA) 模式

// ✅ 正确：AAA 模式
describe("UserService", () => {
  describe("createUser", () => {
    it("should throw ValidationError when email is invalid", async () => {
      // Arrange
      const invalidInput = { email: "not-an-email", password: "validPassword123!" };
      
      // Act & Assert
      await expect(UserService.createUser(invalidInput))
        .rejects.toThrow(ValidationError);
    });
    
    it("should return user with hashed password when input is valid", async () => {
      // Arrange
      const validInput = { email: "[email protected]", password: "validPassword123!" };
      
      // Act
      const user = await UserService.createUser(validInput);
      
      // Assert
      expect(user.email).toBe(validInput.email);
      expect(user.passwordHash).not.toBe(validInput.password);
      expect(bcrypt.compareSync(validInput.password, user.passwordHash)).toBe(true);
    });
  });
});

---

集成测试

• 关键业务流程必须有集成测试
• 使用真实数据库（测试环境）
• 测试数据独立，不互相依赖
• 每个测试前后清理数据

// ✅ 正确：集成测试示例
describe("POST /api/orders", () => {
  let db: Database;
  let auth: AuthHelper;
  
  beforeAll(async () => {
    db = await createTestDatabase();
    auth = new AuthHelper(db);
  });
  
  afterAll(async () => {
    await db.close();
  });
  
  beforeEach(async () => {
    await db.truncate(["users", "orders", "products"]);
  });
  
  it("should create order and reduce inventory", async () => {
    // 准备测试数据
    const user = await auth.createUser({ email: "[email protected]" });
    const product = await db.insert("products", { name: "Widget", stock: 100, price: 9.99 });
    
    // 执行请求
    const response = await request(app)
      .post("/api/orders")
      .set("Authorization", `Bearer ${user.token}`)
      .send({ productId: product.id, quantity: 5 });
    
    // 验证响应
    expect(response.status).toBe(201);
    expect(response.body.order.total).toBe(49.95);
    
    // 验证数据库状态
    const updatedProduct = await db.findById("products", product.id);
    expect(updatedProduct.stock).toBe(95);
  });
});