Mockito模拟所有方法调用和返回

Question

我在用Mock编写单元测试时遇到了一个问题。有一个对象，我需要模拟有很多getter，我在代码中调用它们。但是，这些不是我的单元测试的目的。所以，有没有一种方法我可以模拟所有的方法，而不是一个一个地模拟它们。

下面是代码示例：

public class ObjectNeedToMock{

private String field1;
...
private String field20;

private int theImportantInt;


public String getField1(){return this.field1;}
...

public String getField20(){return this.field20;}

public int getTheImportantInt(){return this.theImportantInt;}

}

public class Service{

public void methodNeedToTest(ObjectNeedToMock objectNeedToMock){
    String stringThatIdontCare1 = objectNeedToMock.getField1();
    ...
    String stringThatIdontCare20 = objectNeedToMock.getField20();
    // do something with the field1 to field20

    int veryImportantInt = objectNeedToMock.getTheImportantInt();
    // do something with the veryImportantInt

    }
}

@Test
public void testMethodNeedToTest() throws Exception {
      ObjectNeedToMock o = mock(ObjectNeedToMock.class);
      when(o.getField1()).thenReturn(anyString());
      ....
      when(o.getField20()).thenReturn(anyString());

      when(o.getTheImportantInt()).thenReturn("1"); //This "1" is the only thing I care

}

那么，有没有一种方法可以避免为无用的“field1”到“field20”写所有的“when”

Answer 1

您可以控制模拟的默认答案。在创建模拟时，请使用：

Mockito.mock(ObjectNeedToMock.class, new Answer() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
        /* 
           Put your default answer logic here.
           It should be based on type of arguments you consume and the type of arguments you return.
           i.e.
        */
        if (String.class.equals(invocation.getMethod().getReturnType())) {
            return "This is my default answer for all methods that returns string";
        } else {
            return RETURNS_DEFAULTS.answer(invocation);
        }
    }
}));