接口测试-mock测试

mock

1.mock是什么

两个系统联调,A完成B开发中,无需B开发完,也可以测试A系统,mock数据便是模拟B系统的接口,快速联调
准确的说:mock是python中一个用于支持单元测试的库,主要功能时使用mock对象代替指定的python对象,已达到模拟对象的行为
不需要关心如何实现的过程,只关注结果即可

2.mock环境搭建

python3.x中,集成到unittest中,直接导入

from unittest import mock

3.mock的优点

1.并行工作:无需等待两者都开发完,一方开发好即可测试
2.模拟无法访问的资源
3.系统具有隔离性:构造虚拟的post请求,不污染数据库中的数据
4.提高覆盖率:模拟500,400,301等不同的类型

4.mock的构成

5.mock中的方法

from unittest.mock import Mock
mock_obj = Mock() # 实例化Mock对象
print(dir(mock_obj))
# ['assert_any_call', 'assert_called', 'assert_called_once', 'assert_called_once_with', 'assert_called_with', 'assert_has_calls', 'assert_not_called', 'attach_mock', 'call_args', 'call_args_list', 'call_count', 'called', 'configure_mock', 'method_calls', 'mock_add_spec', 'mock_calls', 'reset_mock', 'return_value', 'side_effect']

6.Mock中的构造方法

from unittest.mock import Mock
print(dir(Mock))
# ['_NonCallableMock__get_return_value', '_NonCallableMock__get_side_effect', '_NonCallableMock__return_value_doc', '_NonCallableMock__set_return_value', '_NonCallableMock__set_side_effect', '__call__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattr__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_call_matcher', '_extract_mock_name', '_format_mock_call_signature', '_format_mock_failure_message', '_get_child_mock', '_mock_add_spec', '_mock_call', '_mock_check_sig', '_mock_return_value', '_mock_side_effect', 'assert_any_call', 'assert_called', 'assert_called_once', 'assert_called_once_with', 'assert_called_with', 'assert_has_calls', 'assert_not_called', 'attach_mock', 'call_args', 'call_args_list', 'call_count', 'called', 'configure_mock', 'mock_add_spec', 'mock_calls', 'reset_mock', 'return_value', 'side_effect']

1.name

name:mock对象的标识

from unittest import mock
mock_obj = Mock(name = 'xxx')
print(f'name标识{mock_obj}')
# name标识<Mock name='xxx' id='4445533296'>

2.return_value(用的最多)

return_value：该参数指定一个值或者对象

from unittest import mock
mock_obj1 = mock.Mock(return_value=100)
print(f'return_value 指定值{mock_obj1()}')
# return_value 指定值100

3.side_effect

side_effect：该参数指向一个可调用对象（一般是函数）
当mock对象被调用时,如果该参数的返回值是默认的DEFAULT,则mock对象返回return_value指定的值;
否则返回side_effect指定的对象的返回值

from unittest import mock
mock_obj2 = mock.Mock(return_value=100, side_effect=None)
print(f'side_effect 默认值为None,输出return_values的值{mock_obj2()}')
# side_effect 默认值为None,输出return_values的值100

mock_obj3 = mock.Mock(return_value=100, side_effect=[200, 300])
print(f'side_effect 指定值{mock_obj3()},return_value的值被覆盖')
# side_effect 指定值200,return_value被覆盖
print(f'side_effect 迭代输出指定值{mock_obj3()}')
# side_effect 迭代输出指定值300

4.spec

spec：mock对象的属性值

from unittest.mock import Mock
class Foo(object):
    age = 20
    def f1(self):
        return 
    def f2(self, name):
        return name
mock_obj = Mock(spec=Foo)
print(mock_obj.age) 
# <Mock name='mock.age' id='4541307032'>
print(mock_obj.name) 
# AttributeError: Mock object has no attribute 'name' 没有name属性

7.mock 断言

1.assert_called_with()

assert_called_with(参数arg)：检查函数调用参数是否正确

from unittest.mock import Mock
class Foo(object):
    value = 20
    def f1(self, arg):
        return arg
mock_obj = Mock(spec=Foo)
# f1正确的传参姿势
mock_obj.f1(222)
# mock_obj.f1.assert_called_with()  
# 报错，没有传参
# mock_obj.f1.assert_called_with(11)  
# 报错，应该传222,传了11
# mock_obj.f1.assert_called_with(222)  
# 不报错

2.assert_called_once_with()

assert_called_once_with(参数arg)：检查函数调用参数是否正确，但是只调用一次

from unittest.mock import Mock
mock = Mock()
mock()
mock.assert_called_once_with()
# 不会报错
mock()
mock.assert_called_once_with() 
# AssertionError: Expected 'mock' to be called once. Called 2 times.

官方文档

https://docs.python.org/3/library/unittest.mock.html