PowerMockito whenNew thenReturn 不適用於傳遞類

Question

我有以下情況

Class A {
  someMethod() {
    B b = new B();
    b.someMethod();
  }
}

Class B {
  String someMethod() {
    C c = new C();
    return c.someMethod();
  }
}

Class C {
  String someMethod() {
    D d = new D();
    return d.getId()
  }
}

Class D {
  getId() {
    return "id123";
  }
}

我在我的 UT 做什么

@RunWith(PowerMockRunner.class)
@PrepareForTest({A.class, B.class, C.class})
MyTest {
  public void basicTest() {
    D mockDClass = mock(D.class);
    when(mockDClass.getId()).thenReturn("mockedId");
    PowerMockito.whenNew(D.class).withAnyArguments().thenReturn(mockClass);
  }
}

在我的測試中，它應該返回mockedId但控制權轉到實際方法。

知道我可能做錯了什么嗎？ 當我在我測試的whenNew中執行新操作時，whenNew 是否有效？ 而不是我描述的情況。

----------------------UPDATE---------- 寫了一個簡單的模塊來測試以上

public class A {
  public String someMethod() {
    B b = new B();
    return b.someMethod();
  }
}

public class B {
  public String someMethod() {
    C c = new C();
    return c.someMethod();
  }
}

public class C {
  public String someMethod() {
    D d = new D();
    return d.getId();
  }
}

public class D {
  public String getId() {
    return "id123";
  }
}

測試：

import junit.framework.TestCase;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import static org.mockito.Mockito.*;
import static org.mockito.Mockito.mock;

@RunWith(PowerMockRunner.class)
@PrepareForTest({A.class, B.class, C.class})
public class ATest extends TestCase {
  @Test
  public void mockTest() {
    D mockD = mock(D.class);
    when(mockD.getId()).thenReturn("this is from mock");
    PowerMockito.whenNew(D.class).withAnyArguments().thenReturn(mockD);
    A a = new A();
    System.out.println(a.someMethod());
  }
}

而本次測試的output看起來是這樣的：

這個小測試有效，所以我在實際測試中做錯了。

Answer 1

每次您模擬的 object 實例化時，whenNew 都應該有效。 您實際上應該將 'when(D.getId()).thenReturn("mockedId")' 替換為 'when(mockDClass.getId).thenReturn("mockedId")'。 以下代碼片段應該可以工作：

C 測試：

@RunWith(PowerMockRunner.class)
@PrepareForTest({C.class})
public class CTest {

  @Test
  public void someMethodTest() throws Exception {
    D mockDClass = mock(D.class);
    when(mockDClass.getId()).thenReturn("mockedId");
    PowerMockito.whenNew(D.class).withAnyArguments().thenReturn(mockDClass);
    C c = new C();

    String response = c.someMethod();
    verifyNew(D.class).withNoArguments();
    assertEquals("mockedId", response);
  }
}

測試：

@RunWith(PowerMockRunner.class)
public class DTest {

  @Test
  public void testId() throws Exception {
    D mockDClass = mock(D.class);
    when(mockDClass.getId()).thenReturn("mockedId");
    PowerMockito.whenNew(D.class).withAnyArguments().thenReturn(mockDClass);
    D d = new D();

    verifyNew(D.class).withNoArguments();
    String response = d.getId();
    assertEquals("mockedId", response);
  }
}