testing - org.mockito.exceptions.misusing.UnfinishedStubbingException 检测到未完成的 stub

Question

我写了下面的代码:

@RunWith(PowerMockRunner.class)
@PrepareForTest(Integer.class)
public class TestClass{


    @Test
        public void test(){
            PowerMockito.mockStatic(Integer.class);
            when(Integer.parseInt(anyString())).thenReturn(0);
            System.out.println(Integer.parseInt("12"));
        }
}

我收到以下错误消息:

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at com.ctc.dime.services.autopublisher.stores.StoresPublishingServiceTest.test(StoresPublishingServiceTest.java:120)

E.g. thenReturn() may be missing.
Examples of correct stubbing:
    when(mock.isOk()).thenReturn(true);
    when(mock.isOk()).thenThrow(exception);
    doThrow(exception).when(mock).someVoidMethod();
Hints:
 1. missing thenReturn()
 2. you are trying to stub a final method, you naughty developer!

    at org.powermock.api.mockito.internal.invocationcontrol.MockitoMethodInvocationControl.performIntercept(MockitoMethodInvocationControl.java:291)
    at org.powermock.api.mockito.internal.invocationcontrol.MockitoMethodInvocationControl.invoke(MockitoMethodInvocationControl.java:193)
    at org.powermock.core.MockGateway.doMethodCall(MockGateway.java:105)
    at org.powermock.core.MockGateway.methodCall(MockGateway.java:168)
b.....

我做错了什么？

Answer 1

您应该准备使用系统类的类，而不是系统类本身。参见 https://code.google.com/p/powermock/wiki/MockSystem

编辑

参见 Powermock FAQ :

I cannot mock classes in from java.lang, java.net, java.io or other system classes, why?

This is because they're loaded by Java's bootstrap classloader and cannot be byte-code manipulated by PowerMock's classloader. Since PowerMock 1.2.5 there's a work-around, please have a look at this simple example to see how it's done.

我做了一个小测试，它似乎对 java.lang.String 有效，但出于某种原因对 java.lang.Integer 无效。请参阅下面的类(class)。第一种方法失败。第二个 String.format 有效。这对我来说似乎是一个 Powermock 错误。

第三种方法是我常用的解决方法，可以避免静态或系统模拟。我只是创建了一个包保护方法，并在我的测试中监视它。我推荐相同的。这比涉及 Powermock 更好。

import static org.junit.Assert.assertEquals;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.when;

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( { Dummy.class } )
public class TestClass{
    @Test
        public void testStaticIntegerMocking(){
            PowerMockito.mockStatic(Integer.class);
            when(Integer.parseInt(anyString())).thenReturn(0);
            System.out.println(Dummy.parseInt("12"));
        }

    @Test
    public void assertThatMockingStringWorks() throws Exception {
            PowerMockito.mockStatic(String.class);
            final String string = "string";
            final String args = "args";
            final String returnValue = "returnValue";

            when(String.format(string, args)).thenReturn(returnValue);

            final Dummy systemClassUser = new Dummy();
            assertEquals(systemClassUser.format(string, args), returnValue);
    }

    @Test
    public void testSpying(){
        Dummy dummy = new Dummy();
        dummy = spy(dummy);
        doReturn( 0 ).when(dummy).parseIntToBeSpyed(anyString());
        System.out.println(dummy.parseIntToBeSpyed("12"));
    }
}

虚拟类:

import java.io.IOException;

public class Dummy {
    public static Integer parseInt( String string ) {
        return Integer.parseInt(string);
    }

    public String format(String one, String args) throws IOException {
        return String.format(one, args);
    }

    public Integer parseIntToBeSpyed( String string ) {
        return Integer.parseInt(string);
    }
}