自动化测试

1. 测试金字塔

        /  E2E测试  \        少量，慢，脆弱
       /  集成测试    \      适量
      /   单元测试      \    大量，快，稳定

2. 单元测试

2.1 测试框架

2.2 测试结构（AAA 模式）

def test_user_creation():
    # Arrange（准备）
    user_data = {"name": "Alice", "email": "alice@example.com"}

    # Act（执行）
    user = create_user(user_data)

    # Assert（断言）
    assert user.name == "Alice"
    assert user.email == "alice@example.com"

2.3 Mock 与 Stub

from unittest.mock import Mock, patch

# Mock
db = Mock()
db.save.return_value = True
assert db.save({"name": "Alice"}) == True

# Patch
@patch('module.external_api')
def test_with_patch(mock_api):
    mock_api.return_value = {"status": "ok"}
    result = call_api()
    assert result["status"] == "ok"

2.4 测试覆盖率

# 生成覆盖率报告
pytest --cov=myapp --cov-report=html
go test -coverprofile=coverage.out
jest --coverage

3. 集成测试

3.1 数据库集成测试

import pytest
from testcontainers.postgres import PostgresContainer

@pytest.fixture
def postgres():
    with PostgresContainer("postgres:16") as pg:
        yield pg.get_connection_url()

def test_user_repository(postgres):
    repo = UserRepository(postgres)
    repo.create(User(name="Alice"))
    users = repo.find_all()
    assert len(users) == 1

3.2 API 集成测试

from fastapi.testclient import TestClient

def test_create_user():
    client = TestClient(app)
    response = client.post("/api/users", json={
        "name": "Alice",
        "email": "alice@example.com"
    })
    assert response.status_code == 201
    assert response.json()["name"] == "Alice"

3.3 消息队列集成测试

from testcontainers.rabbitmq import RabbitMqContainer

@pytest.fixture
def rabbitmq():
    with RabbitMqContainer("rabbitmq:3-management") as rb:
        yield rb

def test_message_publish(rabbitmq):
    publisher = MessagePublisher(rabbitmq)
    consumer = MessageConsumer(rabbitmq)

    publisher.publish("test_queue", {"event": "created"})
    message = consumer.consume("test_queue", timeout=5)

    assert message["event"] == "created"

4. E2E 测试

4.1 Playwright

test('user login flow', async ({ page }) => {
  await page.goto('/login');

  await page.fill('[data-testid="username"]', 'alice');
  await page.fill('[data-testid="password"]', 'secret');
  await page.click('[data-testid="login-btn"]');

  await expect(page).toHaveURL('/dashboard');
  await expect(page.locator('.welcome')).toContainText('Alice');
});

4.2 Cypress

describe('User Login', () => {
  it('should login successfully', () => {
    cy.visit('/login');
    cy.get('[data-testid="username"]').type('alice');
    cy.get('[data-testid="password"]').type('secret');
    cy.get('[data-testid="login-btn"]').click();
    cy.url().should('include', '/dashboard');
    cy.get('.welcome').should('contain', 'Alice');
  });
});

4.3 E2E 测试最佳实践

• 使用 data-testid 选择器
• 避免依赖实现细节
• 测试关键用户流程
• 设置合理的超时
• 并行执行加速
• 视频和截图记录失败

5. 契约测试

5.1 Pact

消费者驱动契约测试：

// 消费者端
const provider = new Pact({
  consumer: 'UserService',
  provider: 'UserAPI',
});

await provider.addInteraction({
  state: 'user exists',
  uponReceiving: 'a request for user',
  withRequest: {
    method: 'GET',
    path: '/api/users/1',
  },
  willRespondWith: {
    status: 200,
    body: { id: 1, name: 'Alice' },
  },
});

// 提供者端验证
const verifier = new Verifier({
  providerBaseUrl: 'http://localhost:8080',
  pactBrokerUrl: 'http://pact-broker:9292',
  provider: 'UserAPI',
});

await verifier.verify();

6. 性能测试

6.1 负载测试

确定系统在预期负载下的表现：

// k6 脚本
import http from 'k6/http';

export const options = {
  stages: [
    { duration: '2m', target: 100 }, // 上升到100用户
    { duration: '5m', target: 100 }, // 维持100用户
    { duration: '2m', target: 0 }, // 下降到0
  ],
  thresholds: {
    http_req_duration: ['p(95)<500'],
    http_req_failed: ['rate<0.01'],
  },
};

export default function () {
  http.get('http://target/api/users');
}

6.2 压力测试

确定系统的极限：

export const options = {
  stages: [
    { duration: '5m', target: 500 },
    { duration: '5m', target: 1000 },
    { duration: '5m', target: 2000 },
    { duration: '5m', target: 0 },
  ],
};

6.3 浸泡测试

长时间运行检测内存泄漏等问题：

export const options = {
  stages: [
    { duration: '1h', target: 50 },
    { duration: '12h', target: 50 },
    { duration: '1h', target: 0 },
  ],
};

7. CI 中的测试策略

7.1 测试门禁

# GitHub Actions
- name: Run tests
  run: |
    pytest --cov=myapp --cov-fail-under=80
    pytest integration/ -m "not slow"

7.2 测试分层执行

7.3 测试报告

• 覆盖率趋势图
• 测试通过率
• 失败测试分类
• 性能基线对比