1. called - 是否被调用

检查Mock对象是否被调用过

import unittest
from unittest.mock import Mock

def test_called(self):
    mock = Mock()
    mock()  # 调用mock对象
    self.assertTrue(mock.called)

2. call_count - 调用次数

记录Mock对象被调用的总次数

def test_call_count(self):
    mock = Mock()
    mock()
    mock()
    self.assertEqual(mock.call_count, 2)

3. call_args - 最后一次调用参数

获取最后一次调用时使用的参数

def test_call_args(self):
    mock = Mock()
    mock(1, 2, 3, a=4, b=5)
    self.assertEqual(mock.call_args.args, (1, 2, 3))
    self.assertEqual(mock.call_args.kwargs, {'a': 4, 'b': 5})

4. call_args_list - 所有调用参数

获取所有调用的参数列表

def test_call_args_list(self):
    mock = Mock()
    mock(1)
    mock(2, 3)
    mock(a=4)
    
    calls = [call(1), call(2, 3), call(a=4)]
    self.assertEqual(mock.call_args_list, calls)

5. method_calls - 方法调用记录

记录Mock对象上所有方法的调用

def test_method_calls(self):
    mock = Mock()
    mock.method_a(1)
    mock.method_b(2, 3)
    
    expected_calls = [
        call.method_a(1),
        call.method_b(2, 3)
    ]
    self.assertEqual(mock.method_calls, expected_calls)

使用assert_called_with验证调用

def test_assert_called_with(self):
    mock = Mock()
    mock(1, 2, a=3)
    mock.assert_called_with(1, 2, a=3)

使用assert_called_once_with验证单次调用

def test_assert_called_once_with(self):
    mock = Mock()
    mock(1)
    mock.assert_called_once_with(1)
    
    mock(2)  # 第二次调用
    # 下面会失败，因为调用了两次
    # mock.assert_called_once_with(2)

使用assert_has_calls验证调用顺序

def test_assert_has_calls(self):
    mock = Mock()
    mock(1)
    mock(2)
    mock(3)
    
    # 验证调用顺序
    mock.assert_has_calls([call(1), call(2), call(3)])
    
    # 验证调用存在，忽略顺序
    mock.assert_has_calls([call(3), call(1)], any_order=True)

测试用户注册服务

class UserService:
    def __init__(self, db, email_service):
        self.db = db
        self.email_service = email_service
        
    def register_user(self, name, email):
        user_id = self.db.save_user(name, email)
        self.email_service.send_welcome_email(email)
        return user_id

class TestUserService(unittest.TestCase):
    def test_registration_flow(self):
        # 创建Mock依赖
        db_mock = Mock()
        email_mock = Mock()
        
        # 设置模拟返回值
        db_mock.save_user.return_value = 123
        
        # 创建服务实例
        service = UserService(db_mock, email_mock)
        user_id = service.register_user("John", "john@example.com")
        
        # 验证调用
        self.assertEqual(user_id, 123)
        db_mock.save_user.assert_called_once_with("John", "john@example.com")
        email_mock.send_welcome_email.assert_called_once_with("john@example.com")
        self.assertEqual(db_mock.save_user.call_count, 1)