我正在尝试模拟返回类型为 void
的私有(private)字段的方法。在我的测试中,我尝试模拟 aClass.doSomething()
来抛出 IllegalStateException
并且我需要验证是否调用了 recover()
。这是一个例子:
public class ClassToTest implements Runnable {
private ClassToMock aClass;
@Override
public void run() {
try{
aClass.doSomething("some parameter");
} catch(IllegalStateException e) {
logger.error("Something bad happened", e);
recover();
}
}
public void recover(){
logger.info("I am recovering");
}
}
我分别完成了每一部分:
- 模拟私有(private)字段的方法调用
- 模拟具有
void
返回类型的方法 - 抛出异常
- 验证私有(private)方法调用
但我无法将所有内容放在一起。任何帮助表示赞赏
最佳答案
我想我应该详细阐述 GhostCat 的评论:
Stay with Mockito
Mockito 不仅仅是一个模拟框架 - 它是一门学科。如果您仔细阅读 Mockito 的文档并克制自己不要诉诸 PowerMock 等,您将学到良好的 OOP 实践。
Read how to do dependency injection with constructors
Primum non nocere - 首先重构你的代码,如下所示:
public class ClassToTest implements Runnable {
private final ClassToMock aClass;
private final Logger logger;
//injection of collaborators through the constructor
public ClassToTest(ClassToMock aClass, Logger logger) {
this.aClass = aClass;
this.logger = logger;
}
@Override
public void run() {
try{
aClass.doSomething("some parameter");
} catch(IllegalStateException e) {
logger.error("Something bad happened", e);
recover();
}
}
public void recover() { //there is no need for this method to be public - see Effective Java item 13
logger.info("I am recovering");
}
}
现在您的代码可以使用 Mockito 进行测试而无需诉诸更复杂的模拟框架:
//mocks
@Mock ClassToMock classToMock;
@Mock Logger mockLogger;
//system under test
ClassToTest classToTest;
@Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks();
classToTest = new ClassToTest(classToMock, mockLogger);
}
@Test
public void whenRun_thenDoesSomethingWithSomeParameter() {
//act
classToTest.run();
//assert
verify(classToMock).doSomething(eq("some parameter"));
}
@Test
public void givenAnIllegalStateForAClass_whenRun_thenLogsError() {
//arrange
IllegalStateException e = new IllegalStateException();
when(classToMock.doSomething(anyString()).thenThrow(e);
//act
classToTest.run();
//assert
verify(mockLogger).error(eq("Something bad happened"), same(e));
}
@Test
public void givenAnIllegalStateForAClass_whenRun_thenLogsRecovery() {
//arrange
when(classToMock.doSomething(anyString()).thenThrow(new IllegalStateException());
//act
classToTest.run();
//assert
verify(mockLogger).info(eq("I am recovering"));
}
关于Java模拟私有(private)字段的方法,返回null,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/42801666/