有没有办法使用 EasyMock 部分模拟对象？

Question

例如假设我有这个课程：

public class Foo Implements Fooable {
  public void a() {
    // does some stuff
    bar = b();
    // moar coadz
  }
  public Bar b() {
    // blah
  }
  // ...
}

我想测试Foo.a。我想模拟Foo.b，因为我正在单独测试该方法。我想象的是这样的：

public class FooTest extends TestCase {
  public void testA() {
    Fooable foo = createPartialMock(
      Fooable.class,  // like with createMock
      Foo  // class where non-mocked method implementations live
    );

    // Foo's implementation of b is not used.
    // Rather, it is replaced with a dummy implementation
    // that records calls that are supposed to be made;
    // and returns a hard coded value (i.e. new Bar()).
    expect(foo.b()).andReturn(new Bar());

    // The rest is the same as with createMock:
    //   1. Stop recording expected calls.
    //   2. Run code under test.
    //   3. Verify that recorded calls were made.
    replay(foo);
    foo.a();
    verify(foo);
  }
}

我知道我可以编写自己的 Foo 子类来为我做这种事情。但如果我不必这样做，我不想这样做，因为它很乏味，即应该自动化。

Answer 1

在 EasyMock 3.0+ 中，您可以使用 mockbuilder 创建 Partial mock

EasyMock.createMockBuilder(class).addMockedMethod("MethodName").createMock();

Answer 2

我猜你可以使用 EasyMock 扩展库来做到这一点。你可以在这里找到一个简单的例子Partial Mocking

Answer 3

OP 似乎（？）暗示子类化比部分模拟更困难或更乏味。我建议值得重新考虑。

例如在测试类中：

  Foo dummyFoo = new Foo() {
      @Override public Bar b() { return new Bar(); }
   };

与使用 EasyMock 相比，执行 OP 所述的操作，看起来更简单，并且不太容易出现其他问题（忘记重播/验证/等）。

Answer 4

我会想办法升级到 JUnit 4，并使用类扩展。 （实际上，我会使用 Mockito 而不是 EasyMock，但我们不要重写你的整个测试套件。）如果你不能，那么你总是可以创建自己的间谍：

public class FooTest extends TestCase {
    public static class FooSpy extends Foo {
        private final Fooable mockFoo;

        FooSpy(Fooable mockFoo) {
            this.mockFoo = mockFoo;
        }

        public Bar b() {
            return mockFoo.b();
        }
    }

    public void testA() {
        Fooable mockFoo = createMock(Foo.class);
        Fooable fooSpy = new FooSpy(mockFoo);

        // Foo's implementation of b is not used.
        // Rather, it is replaced with a dummy implementation
        // that records calls that are supposed to be made;
        // and returns a hard coded value (i.e. new Bar()).
        expect(mockFoo.b()).andReturn(new Bar());

        // The rest is the same as with createMock:
        // 1. Stop recording expected calls.
        // 2. Run code under test.
        // 3. Verify that recorded calls were made.
        replay(mockFoo);
        foo.a();
        verify(foo);
    }

}