如何模擬/監視/存根超類的方法

Question

我實現了一個類B，它是現有抽象類A的子類。

抽象類（本質上）：

public abstract class A {
   public A(Properties p, ArrayList<XXX> list) {
      ...
   }

   // There is no 0-arg constructor

   protected int doSomeWork() {
      return ...;
   }

   protected SomeObject[] findObjectsByQuery(String query) {
      return ...;
   }
}

我自己的課

public class B extends A {

    // this is the method I want to test
    protected int doSomeWork() {
       ...
       // calling method of super class
       // this call I want to mock/stub/whatever
       // to either return null or a mock object
       SomeObject[] myobjects = findObjectsByQuery(queryString);
       ...
    }
}

如您所見，我要測試的方法也受到保護。 這就是為什么我創建了一個內部類Btest，它僅從B繼承用於測試：

private class Btest extends B {

   public Btest(Properties prop) {
      super(prop, null);
   }

   public int doSomeWork() {
      return super.doSomeWork();
   }
}

我的測試方法是將Mockito與PowerMock結合使用。 這是我到目前為止的內容：

@RunWith(PowerMockRunner.class)
@PrepareForTest(A.class)
public class Tester {

   @Test
   public void testWrongQueryString() throws Exception {
      Properties prop = new Properties();
      Btest testObject = new Btest(prop);

      // what am I supposed to do here?
      // essentially I want to do something in the lines of
      // PowerMockito.when(/* there is a call to A.findObjectsByQuery or B.findObjectsByQuery with parameter "QueryString" */)
      //             .thenReturn(null);

      int result = testObject.doSomeWork();

      Assert.assertEquals(2, result);
   }
}

這就是我嘗試過的：

// gives an InvocationTargetException
Btest spy = PowerMockito.spy(testObject);
PowerMockito.when(spy, "findObjectsByQuery", "QueryString").thenReturn(null);

// will not return NULL
A mock = Mockito.mock(A.class);
PowerMockito.when(mock, "findObjectsByQuery", "QueryString").thenReturn(null);

我該怎么辦？

Answer 1

我認為應該是這樣的：

Btest spy = PowerMockito.spy(testObject);
PowerMockito.doReturn(null).when(spy, "findObjectsByQuery");

Answer 2

我的問題是我調用了要用testObject.doSomeWork()而不是spy.doSomeWork()進行測試的方法

它是這樣的：

Btest spy = PowerMockito.spy(testObject);
PowerMockito.doReturn(null).when(spy, "findObjectsByQuery", Mockito.someString());

與

int result = spy.doSomeWork();