如何在easymock中模拟一个返回其参数之一的方法？

mocking java capture easymock

2022-09-01 09:21:36

public Object doSomething(Object o);我想嘲笑一下。它应该只返回其参数。我试过了：

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

但是没有成功，我只得到一个断言错误作为.有什么想法吗？java.lang.AssertionError: Nothing captured yet

答案 1

好吧，最简单的方法是在IAnswer实现中使用捕获...在内联执行此操作时，您当然必须声明它。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，而不依赖于一些上下文信息。这每次对我来说都是诀窍。

答案 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];
    }

}

我在类的javadoc中写了一个快速的“如何”。

希望这有帮助。