# content of test_basic.py
def func(x):
    return x + 1

# 简单断言
def test_basic():
    assert func(3) == 4

import pytest

@pytest.mark.parametrize("input,expected", [
    (1, 2),
    (2, 3),
    (3, 4),
])
def test_addition(input, expected):
    assert input + 1 == expected

@pytest.mark.slow
def test_slow_stuff():
    pass

# 运行: pytest -m slow
pytest -m "not slow"  # 跳过慢速测试

import pytest

@pytest.fixture
def db_connection():
    conn = create_real_database_connection()
    yield conn
    conn.close()

def test_with_db(db_connection):
    result = db_connection.query("SELECT ...")
    assert result is not None

"""基础单元测试示例"""
import pytest


def add(a, b):
    """两数相加"""
    return a + b


def test_add_basic():
    """测试基本加法"""
    result = add(2, 3)
    assert result == 5


def test_add_negative():
    """测试负数相加"""
    result = add(-1, -2)
    assert result == -3


def test_add_mixed():
    """测试正负混合"""
    result = add(-1, 1)
    assert result == 0


#  parametrize 示例
@pytest.mark.parametrize("a, b, expected", [
    (0, 0, 0),
    (1, 2, 3),
    (-1, 1, 0),
    (100, 200, 300),
])
def test_add_parametrized(a, b, expected):
    """参数化测试add函数"""
    assert add(a, b) == expected

"""进阶测试模式与避坑示例"""
import pytest


class BankAccount:
    """模拟银行账户"""
    
    def __init__(self, initial_balance=0):
        self.balance = initial_balance
    
    def deposit(self, amount):
        if amount <= 0:
            raise ValueError("存款金额必须大于0")
        self.balance += amount
    
    def withdraw(self, amount):
        if amount <= 0:
            raise ValueError("取款金额必须大于0")
        if amount > self.balance:
            raise ValueError("余额不足")
        self.balance -= amount


def test_withdraw_insufficient_funds():
    """测试余额不足情况"""
    account = BankAccount(100)
    
    with pytest.raises(ValueError, match="余额不足"):
        account.withdraw(200)


def test_withdraw_negative_amount():
    """测试负数取款 - 应该失败"""
    account = BankAccount(100)
    
    # 正确的断言：期望抛出异常
    with pytest.raises(ValueError, match="取款金额必须大于0"):
        account.withdraw(-50)


def test_deposit_zero_fails():
    """测试零存款应该失败"""
    account = BankAccount()
    
    with pytest.raises(ValueError, match="存款金额必须大于0"):
        account.deposit(0)


def test_account_initial_balance():
    """测试账户初始余额"""
    account = BankAccount(50)
    assert account.balance == 50
    assert account.balance is not None


def test_account_negative_deposit():
    """测试负数存款"""
    account = BankAccount()
    
    # 匹配错误信息
    with pytest.raises(ValueError) as exc_info:
        account.deposit(-100)
    
    # 验证异常信息内容
    assert "存款金额必须大于0" in str(exc_info.value)

"""完整的自动化测试套件示例"""
import pytest
import tempfile
import os
from pathlib import Path


# Fixture：临时文件
@pytest.fixture
def temp_dir():
    """创建临时目录，测试结束自动清理"""
    with tempfile.TemporaryDirectory() as tmpdir:
        yield Path(tmpdir)


@pytest.fixture
def sample_data():
    """提供测试用的样本数据"""
    return {
        "name": "测试用户",
        "age": 25,
        "email": "test@example.com"
    }


class TestUserManagement:
    """用户管理测试类"""
    
    def test_create_user(self, sample_data):
        """测试创建用户"""
        assert sample_data["name"] == "测试用户"
        assert sample_data["age"] == 25
        assert "@" in sample_data["email"]
    
    def test_user_email_format(self, sample_data):
        """测试邮箱格式验证"""
        parts = sample_data["email"].split("@")
        assert len(parts) == 2
        assert len(parts[1]) > 0
    
    def test_user_name_not_empty(self, sample_data):
        """测试用户名不为空"""
        assert sample_data["name"].strip() != ""


class TestFileOperations:
    """文件操作测试"""
    
    def test_temp_file_creation(temp_dir):
        """测试临时文件创建"""
        test_file = temp_dir / "test.txt"
        test_file.write_text("Hello Test")
        assert test_file.exists()
        assert test_file.read_text() == "Hello Test"
    
    def test_temp_file_cleanup(temp_dir):
        """测试临时文件自动清理"""
        # 在此之后，temp_dir及其内容会自动删除
        pass
    
    def test_content_integrity(temp_dir):
        """测试内容完整性"""
        (temp_dir / "data.json").write_text('{"key": "value"}')
        data = eval((temp_dir / "data.json").read_text())
        assert data == {"key": "value"}