3.5

1. 单元测试的作用
   验证代码最小单元（函数、类）的正确性
   提前发现逻辑错误，降低后期调试成本
2. 代码示例：使用 Python unittest 测试学生类
   python
   运行
   import unittest
   from student import Student # 假设Student类在student.py中

class TestStudent(unittest.TestCase):
def test_calculate_grade(self):
# 测试不同成绩的等级
student_a = Student("S001", "张三", 95)
self.assertEqual(student_a.calculate_grade(), "A")

    student_b = Student("S002", "李四", 75)
    self.assertEqual(student_b.calculate_grade(), "C")
    
    student_c = Student("S003", "王五", 59)
    self.assertEqual(student_c.calculate_grade(), "D")

if name == "main":
unittest.main()
3. 自动化测试集成
使用持续集成工具（如 Jenkins、GitHub Actions）
每次代码提交后自动运行测试
4. 代码示例：GitHub Actions 配置
yaml
name: Run Unit Tests
on: [push]

jobs:
test:
runs-on: ubuntu-latest
steps:
- name: Checkout code
uses: actions/checkout@v4

  - name: Set up Python
    uses: actions/setup-python@v5
    with:
      python-version: 3.10
  
  - name: Install dependencies
    run: |
      python -m pip install --upgrade pip
      pip install -r requirements.txt
  
  - name: Run tests
    run: |
      python -m unittest discover -s tests