如何通过 EasyMockRule 或 EasyMockRunner 委托来使用 EasyMockSupport？

Question

在通过委派（而不是继承）使用EasyMockSupport时，是否可以同时利用EasyMockSupport and EasyMockRule (or EasyMockRunner)？

换句话说：如何让 EasyMockSupport 知道 EasyMockRule 创建的模拟？

这是一个 MWE，展示了我面临的问题：

// Class under test
public class MyClass {
    private Collaborator collaborator;
    public MyClass() {
        collaborator = new Collaborator();
    }

    // Method under test
    public int myMethod() {
        return collaborator.mockedMethod() + 1;
    }
}

// Class to be mocked
public class Collaborator {
    public int mockedMethod() {
        return 1;
    }
}

// Test case
public class MyClassTest {
    private EasyMockSupport easyMockSupport = new EasyMockSupport();
    @Rule public EasyMockRule easyMockRule = new EasyMockRule(this);

    @TestSubject private MyClass testSubject = new MyClass();
    @Mock private Collaborator collaboratorMock;

    @Test public void testMyMethod() {
        EasyMock.expect(collaboratorMock.mockedMethod()).andReturn(2);
        easyMockSupport.replayAll();

        int result = testSubject.myMethod();
        Assert.assertEquals("Should return 2+1 when successfully mocked", 3, result);
        // throws java.lang.AssertionError: expected: <3> but was: <1>
    }
}

测试失败，但如果 MyClassTest 扩展 EasyMockSupport，则测试通过。（但我不能将继承用于我正在做的事情，因此我的问题。）

我对这种行为的理解是，在我的例子中，EasyMockSupport 不知道 Collaborator 模拟，所以调用 replayAll() 没有效果，模拟仍然是在 testSubject.myMethod() 中调用时处于记录状态（因此 mockedMethod() 返回 0）。事实上，injectMocks() documentation 说：

If the parameter extends EasyMockSupport, the mocks will be created using it to allow replayAll/verifyAll to work afterwards

但是当使用委托时，参数（即测试 class）不会扩展 EasyMockSupport。有没有我遗漏或不可能的东西？

旁注：我正在使用 EasyMock 3.6。理想情况下，我想找到一个保留该版本的解决方案，但请随时指出在以后的版本中是否有相关的 feature/bugfix。

在此先感谢您的帮助！

Answer 1

不容易。但是，这是一个有用的用例，因此我建议您填写 issue.

同时，我们需要让规则知道 EasyMocksSupport。这是一个解决方案。

import org.easymock.EasyMock;
import org.easymock.EasyMockRule;
import org.easymock.EasyMockSupport;
import org.easymock.Mock;
import org.easymock.TestSubject;
import org.easymock.internal.MocksControl;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;

import java.lang.reflect.Field;

// Class under test
class MyClass {
    private Collaborator collaborator;
    public MyClass() {
        collaborator = new Collaborator();
    }

    // Method under test
    public int myMethod() {
        return collaborator.mockedMethod() + 1;
    }
}

// Class to be mocked
class Collaborator {
    public int mockedMethod() {
        return 1;
    }
}

class ExtendedEasyMockSupport extends EasyMockSupport {
    public void addMock(Object mock) {
        if(EasyMockSupport.getMockedClass(mock) == null)  {
            throw new IllegalArgumentException(mock + " is not a mock");
        }
        MocksControl control = MocksControl.getControl(mock);
        controls.add(control);
    }

    public void addAllMocks(Object testClass) {
        Field[] fields = testClass.getClass().getDeclaredFields();
        for (Field field : fields) {
            Mock annotation = field.getAnnotation(Mock.class);
            if(annotation != null) {
                field.setAccessible(true);
                Object mock;
                try {
                    mock = field.get(testClass);
                } catch (IllegalAccessException e) {
                    throw new RuntimeException(e);
                }
                addMock(mock);
            }
        }
    }
}

// Test case
public class MyClassTest {
    private final ExtendedEasyMockSupport easyMockSupport = new ExtendedEasyMockSupport();
    @Rule
    public EasyMockRule easyMockRule = new EasyMockRule(this);

    @TestSubject
    private final MyClass testSubject = new MyClass();

    @Mock
    private Collaborator collaboratorMock;

    @Before
    public void before() {
        easyMockSupport.addAllMocks(this);
    }

    @Test
    public void testMyMethod() {
        EasyMock.expect(collaboratorMock.mockedMethod()).andReturn(2);
        easyMockSupport.replayAll();

        int result = testSubject.myMethod();
        Assert.assertEquals("Should return 2+1 when successfully mocked", 3, result);
        // throws java.lang.AssertionError: expected: <3> but was: <1>
    }
}

如何通过 EasyMockRule 或 EasyMockRunner 委托来使用 EasyMockSupport？

How to use EasyMockSupport through delegation with EasyMockRule or EasyMockRunner?

java

testing

unit-testing

easymock