Question

public Object doSomething(Object o);我想嘲笑。它应该只返回它的参数。我试过了：

Capture<Object> copyCaptcher = new Capture<Object>();
expect(mock.doSomething(capture(copyCaptcher)))
        .andReturn(copyCatcher.getValue());

但没有成功，我只得到一个AssertionError java.lang.AssertionError: Nothing captured yet。有什么想法吗？

Answer 1

嗯，最简单的方法是在IAnswer实现中使用Capture ...当进行内联时，你当然必须声明final。

MyService mock = createMock(MyService.class);

final Capture<ParamAndReturnType> myCapture = new Capture<ParamAndReturnType>();
expect(mock.someMethod(capture(myCapture))).andAnswer(
    new IAnswer<ParamAndReturnType>() {
        @Override
        public ParamAndReturnType answer() throws Throwable {
            return myCapture.getValue();
        }
    }
);
replay(mock)

这可能是最精确的方式，而不依赖于某些上下文信息。这对我来说每次都有诀窍。

Answer 2

我一直在寻找相同的行为，最后写了以下内容：

import org.easymock.EasyMock;
import org.easymock.IAnswer;

/**
 * Enable a Captured argument to be answered to an Expectation.
 * For example, the Factory interface defines the following
 * <pre>
 *  CharSequence encode(final CharSequence data);
 * </pre>
 * For test purpose, we don't need to implement this method, thus it should be mocked.
 * <pre>
 * final Factory factory = mocks.createMock("factory", Factory.class);
 * final ArgumentAnswer<CharSequence> parrot = new ArgumentAnswer<CharSequence>();
 * EasyMock.expect(factory.encode(EasyMock.capture(new Capture<CharSequence>()))).andAnswer(parrot).anyTimes();
 * </pre>
 * Created on 22 juin 2010.
 * @author Remi Fouilloux
 *
 */
public class ArgumentAnswer<T> implements IAnswer<T> {

    private final int argumentOffset;

    public ArgumentAnswer() {
        this(0);
    }

    public ArgumentAnswer(int offset) {
        this.argumentOffset = offset;
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public T answer() throws Throwable {
        final Object[] args = EasyMock.getCurrentArguments();
        if (args.length < (argumentOffset + 1)) {
            throw new IllegalArgumentException("There is no argument at offset " + argumentOffset);
        }
        return (T) args[argumentOffset];
    }

}

我在班级的javadoc中写了一个快速的“how to”。

希望这有帮助。

Answer 3

捕获用于测试之后传递给模拟的值。如果您只需要一个模拟来返回一个参数（或从参数计算出的某个值），您只需要实现IAnswer。

如果你想要一个可重用的方法来传递参数X，请参阅“Remi Fouilloux”的实现，但忽略他在示例中使用Capture。

如果你只是想像“do_the_trick”的例子那样内联它，那么Capture就是一个红色的鲱鱼。这是简化版本：

MyService mock = createMock(MyService.class);
expect(mock.someMethod(anyObject(), anyObject()).andAnswer(
    new IAnswer<ReturnType>() {
        @Override
        public ReturnType answer() throws Throwable {
            // you could do work here to return something different if you needed.
            return (ReturnType) EasyMock.getCurrentArguments()[0]; 
        }
    }
);
replay(mock)

Answer 4

基于@does_the_trick并使用lambdas，您现在可以编写以下内容：

MyService mock = EasyMock.createMock(MyService.class);

final Capture<ParamAndReturnType> myCapture = EasyMock.newCapture();
expect(mock.someMethod(capture(myCapture))).andAnswer(() -> myCapture.getValue());

或没有捕获@thetoolman建议

expect(mock.someMethod(capture(myCapture)))
.andAnswer(() -> (ParamAndReturnType)EasyMock.getCurrentArguments()[0]);

Answer 5

嗯，如果我理解你的问题，我认为你可能会使它复杂化。

Object someObject = .... ; expect(mock.doSomething(someObject)).andReturn(someObject);

应该工作得很好。请记住，您提供的是预期参数和返回值。所以在两个作品中使用相同的对象。

如何在easymock中模拟一个返回其中一个参数的方法？

5 个答案: