powermock mocking构造函数通过whennew()不能与匿名类一起使用

Question

我有一个DummyResource类和一个DummyTarget文件,以及一个测试类TestDummyResource,如下所示,但是DummyResource dr = mock(DummyResource.class)当我在普通类中调用构造函数时,模拟对象才起作用,当它在匿名类中调用时,它调用实际的构造函数而不是使用被模拟的对象.

版本:

powermock 1.4.12 mockito 1.9.0 junit 4.8.2

DummyTarget.java:

import java.io.IOException;
import java.io.OutputStream;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.StreamingOutput;


public class DummyTarget {
    public StreamingOutput testMocking() {
        return new StreamingOutput() {
            @Override
            public void write(OutputStream arg0) throws IOException, WebApplicationException {
                new DummyResource();
            }
        };
    }
}

DummyResource.java:

package com.smin.dummy;

public class DummyResource {
    public DummyResource() {
        System.out.println("mock failure");
    }
}

TestDummyResource.java:

package com.smin.dummy;

import static org.mockito.Mockito.mock;

import java.io.IOException;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.StreamingOutput;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest({DummyResource.class,DummyTarget.class})
public class TestDummyResource  {

    @Before
    public void setUp() throws Exception {
        DummyResource dr = mock(DummyResource.class);
        PowerMockito.whenNew(DummyResource.class).withNoArguments().thenReturn(dr);
    }

    @Test
    public void testMocked() throws WebApplicationException, IOException {
        new DummyResource(); // it uses the mocked object dr here, 
                             //doesn't print "mock failure"
        StreamingOutput sop = new DummyTarget().testMocking();
        sop.write(null);     // it calls DummyResource's constructor,
                             // prints ""mock failure"" here
    }
}

Answer 1

你需要准备调用构造函数的类,而不是调用构造函数的类,以下内容应该修复你:

@PrepareForTest(DummyTarget.class)

有关更多信息,请查看此页面.

Answer 2

看起来匿名类可能会继承定义它的类的包.你能试试通配符PrepareForTest吗？:

@PrepareForTest("com.smin.dummy.*")

如果这不起作用,您可以尝试霰弹枪PrepareEverythingForTest注释.

Answer 3

实际上,您必须准备测试构造函数调用的类,而不是调用构造函数的类.请参阅https://github.com/jayway/powermock/wiki/MockConstructor.

在您的情况下,您应该使用@PrepareForTest(DummyTarget.class)