1.软件测试
软件测试是一种用来鉴定软件的正确性、完整性、安全性和质量的过程。主要包括单元测试、集成测试和功能测试等。
1.1 单元测试
主要由开发人员进行，确保程序单元符合预期。
1.2 集成测试
主要由开发人员进行，测试整体程序等功能和性能。
1.3 功能测试
主要由测试人员进行，测试程序是否符合预期。
2.单元测试内容
- 模块接口测试
- 模块局部数据结构测试
- 模块边界条件测试
- 模块中所有独立执行通路测试
- 模块的各条错误处理通路测试
- 模块的非法输入测试
- 代码重用测试
- 系统兼容测试
3.单元测试最佳实践
3.1 三到五步（Setup，输入，调用，输出，TearDown）
3.2 一致性（任何时候同样的输入需要同样的结果）
反例：
Date date = new Date();
Random.next();3.3 原子性
所有的测试只有两种结果（成功或失败，不能部分测试通过）
3.4 单一职责
一个测试只验证一个行为
3.5 独立无耦合
- 单元测试之间无相互调用（单元测试执行顺序无关）
- 单元测试之间不能共享
3.6 隔离外部调用（不使用不依赖具体、真实的数据，例如：数据库、网络、外部文件等）
3.7 自描述（开发级文档）
3.8 单元测试逻辑
3.9 断言（包含具体的错误信息）
4.Mockito
单元测试开发中，我们经常会遇到测试的类有很多依赖的类、对象、资源，从而形成巨大的依赖树，mock可以模拟外部依赖，适应单元测试。
5.Mockito示例
模拟对象
// 模拟LinkedList 的一个对象
LinkedList mockedList = mock(LinkedList.class);
// 此时调用get方法，会返回null，因为还没有对方法调用的返回值做模拟
System.out.println(mockedList.get(0)); 模拟方法调用的返回值
// 模拟获取第一个元素时，返回字符串first。 给特定的方法调用返回固定值在官方说法中称为stub。
when(mockedList.get(0)).thenReturn("first");
// 此时打印输出first
System.out.println(mockedList.get(0)); 模拟方法调用抛出异常
// 模拟获取第二个元素时，抛出RuntimeException
when(mockedList.get(1)).thenThrow(new RuntimeException());
// 此时将会抛出RuntimeException
System.out.println(mockedList.get(1));如果一个函数没有返回值类型，那么可以使用此方法模拟异常抛出
doThrow(new RuntimeException("clear exception")).when(mockedList).clear();
mockedList.clear();模拟调用方法时的参数匹配
// anyInt()匹配任何int参数，这意味着参数为任意值，其返回值均是element
when(mockedList.get(anyInt())).thenReturn("element");
// 此时打印是element
System.out.println(mockedList.get(999));模拟方法调用次数
// 调用add一次
mockedList.add("once");
// 下面两个写法验证效果一样，均验证add方法是否被调用了一次
verify(mockedList).add("once");
verify(mockedList, times(1)).add("once"); 校验行为
// mock creation
List mockedList = mock(List.class);
// using mock object
mockedList.add("one");
mockedList.clear();
//verification
verify(mockedList).add("one");
verify(mockedList).clear();模拟方法调用(Stubbing)
//You can mock concrete classes, not just interfaces
LinkedList mockedList = mock(LinkedList.class);
//stubbing
when(mockedList.get(0)).thenReturn("first");
when(mockedList.get(1)).thenThrow(new RuntimeException());
//following prints "first"
System.out.println(mockedList.get(0));
//following throws runtime exception
System.out.println(mockedList.get(1));
//following prints "null" because get(999) was not stubbed
System.out.println(mockedList.get(999));
verify(mockedList).get(0);参数匹配
//stubbing using built-in anyInt() argument matcher
when(mockedList.get(anyInt())).thenReturn("element");
//stubbing using custom matcher (let's say isValid() returns your own matcher implementation):
when(mockedList.contains(argThat(isValid()))).thenReturn("element");
//following prints "element"
System.out.println(mockedList.get(999));
//you can also verify using an argument matcher
verify(mockedList).get(anyInt());
//argument matchers can also be written as Java 8 Lambdas
verify(mockedList).add(someString -> someString.length() > 5);校验方法调用次数
//using mock
mockedList.add("once");
mockedList.add("twice");
mockedList.add("twice");
mockedList.add("three times");
mockedList.add("three times");
mockedList.add("three times");
//following two verifications work exactly the same - times(1) is used by default
verify(mockedList).add("once");
verify(mockedList, times(1)).add("once");
//exact number of invocations verification
verify(mockedList, times(2)).add("twice");
verify(mockedList, times(3)).add("three times");
//verification using never(). never() is an alias to times(0)
verify(mockedList, never()).add("never happened");
//verification using atLeast()/atMost()
verify(mockedList, atLeastOnce()).add("three times");
verify(mockedList, atLeast(2)).add("five times");
verify(mockedList, atMost(5)).add("three times");模拟无返回方法抛出异常
doThrow(new RuntimeException()).when(mockedList).clear();
//following throws RuntimeException:
mockedList.clear();校验方法调用顺序
// A. Single mock whose methods must be invoked in a particular order
List singleMock = mock(List.class);
//using a single mock
singleMock.add("was added first");
singleMock.add("was added second");
//create an inOrder verifier for a single mock
InOrder inOrder = inOrder(singleMock);
//following will make sure that add is first called with "was added first, then with "was added second"
inOrder.verify(singleMock).add("was added first");
inOrder.verify(singleMock).add("was added second");
// B. Multiple mocks that must be used in a particular order
List firstMock = mock(List.class);
List secondMock = mock(List.class);
//using mocks
firstMock.add("was called first");
secondMock.add("was called second");
//create inOrder object passing any mocks that need to be verified in order
InOrder inOrder = inOrder(firstMock, secondMock);
//following will make sure that firstMock was called before secondMock
inOrder.verify(firstMock).add("was called first");
inOrder.verify(secondMock).add("was called second");
// Oh, and A + B can be mixed together at will校验方法是否从未调用
//using mocks - only mockOne is interacted
mockOne.add("one");
//ordinary verification
verify(mockOne).add("one");
//verify that method was never called on a mock
verify(mockOne, never()).add("two");
//verify that other mocks were not interacted
verifyZeroInteractions(mockTwo, mockThree);快速创建Mock对象
public class ArticleManagerTest {
@Mock private ArticleCalculator calculator;
@Mock private ArticleDatabase database;
@Mock private UserProvider userProvider;
@Before
public void before(){
MockitoAnnotations.initMocks(this);
}
}自定义返回不同结果
when(mock.someMethod("some arg"))
.thenThrow(new RuntimeException()) // 第一次会抛出异常
.thenReturn("foo"); // 第二次会返回这个结果
//First call: throws runtime exception:
mock.someMethod("some arg"); // 第一次
//Second call: prints "foo"
System.out.println(mock.someMethod("some arg")); // 第二次
//Any consecutive call: prints "foo" as well (last stubbing wins).
System.out.println(mock.someMethod("some arg")); // 第n次(n> 2)，依旧以最后返回最后一个配置对返回结果进行拦截
when(mock.someMethod(anyString())).thenAnswer(new Answer() {
Object answer(InvocationOnMock invocation) {
Object[] args = invocation.getArguments();
Object mock = invocation.getMock();
return "called with arguments: " + args;
}
});
//the following prints "called with arguments: foo"
System.out.println(mock.someMethod("foo"));Mock函数操作
可以通过doThrow(), doAnswer(), doNothing(), doReturn() and doCallRealMethod() 来自定义函数操作。
暗中调用真实对象
List list = new LinkedList();
List spy = spy(list);
//optionally, you can stub out some methods:
when(spy.size()).thenReturn(100);
//using the spy calls *real* methods
spy.add("one");
spy.add("two");
//prints "one" - the first element of a list
System.out.println(spy.get(0));
//size() method was stubbed - 100 is printed
System.out.println(spy.size());
//optionally, you can verify
verify(spy).add("one");
verify(spy).add("two");改变默认返回值
Foo mock = mock(Foo.class, Mockito.RETURNS_SMART_NULLS);
Foo mockTwo = mock(Foo.class, new YourOwnAnswer());捕获函数的参数值
ArgumentCaptor<Person> argument = ArgumentCaptor.forClass(Person.class);
verify(mock).doSomething(argument.capture());
assertEquals("John", argument.getValue().getName());部分Mock
//you can create partial mock with spy() method:
List list = spy(new LinkedList());
//you can enable partial mock capabilities selectively on mocks:
Foo mock = mock(Foo.class);
//Be sure the real implementation is 'safe'.
//If real implementation throws exceptions or depends on specific state of the object then you're in trouble.
when(mock.someMethod()).thenCallRealMethod();重置Mock
List mock = mock(List.class);
when(mock.size()).thenReturn(10);
mock.add(1);
reset(mock);
//at this point the mock forgot any interactions & stubbing序列化
List<Object> list = new ArrayList<Object>();
List<Object> spy = mock(ArrayList.class, withSettings()
.spiedInstance(list)
.defaultAnswer(CALLS_REAL_METHODS)
.serializable());检查超时
//passes when someMethod() is called within given time span
verify(mock, timeout(100)).someMethod();
//above is an alias to:
verify(mock, timeout(100).times(1)).someMethod();
//passes when som`eMethod() is called *exactly* 2 times within given time span
verify(mock, timeout(100).times(2)).someMethod();
//passes when someMethod() is called *at least* 2 times within given time span
verify(mock, timeout(100).atLeast(2)).someMethod();
//verifies someMethod() within given time span using given verification mode
//useful only if you have your own custom verification modes.
verify(mock, new Timeout(100, yourOwnVerificationMode)).someMethod();Mock详情
Mockito.mockingDetails(someObject).isMock();
Mockito.mockingDetails(someObject).isSpy();