Partial Mock Private Method with PowerMock-Mockito

Question

I am new to Mockito and PowerMock. I need to test some legacy code which has a private method I have to mock. I am considering using the private partial mocking feature from PowerMock, I tried to mimic the example from the link, but it failed. I have no idea what's wrong with it. Could you help to check it? Thanks

Here's the class to-be-tested:

package test;

public class ClassWithPrivate
{

     private String getPrivateString() {
       return "PrivateString";
     }

     private String getPrivateStringWithArg(String s) {
       return "PrivateStringWithArg";
     }

 }

And This is the Test Code:

package test;

import static org.mockito.Mockito.*;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.api.support.membermodification.MemberMatcher;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassWithPrivate.class)
public class ClassWithPrivateTest {

    @Test
    public void testGetPrivateString() {

         ClassWithPrivate spy = PowerMockito.spy(new ClassWithPrivate());

         PowerMockito.doReturn("Do").when(spy, method(ClassWithPrivate.class, "getPrivateStringWithArg", String.class)).withArguments(anyString());

    }

}

EDIT When I tried to compile the code, it failed with the following errors:

ClassWithPrivateTest.java:26: unreported exception java.lang.Exception; must be caught or declared to be thrown
     PowerMockito.doReturn("Do").when(spy, method(ClassWithPrivate.class, "getPrivateStringWithArg", String.class)).withArguments(anyString());
                                     ^
ClassWithPrivateTest.java:26: unreported exception java.lang.Exception; must be caught or declared to be thrown
     PowerMockito.doReturn("Do").when(spy, method(ClassWithPrivate.class, "getPrivateStringWithArg", String.class)).withArguments(anyString());

For me the test works as expected. What do you mean with "it failed". Is there an exception, when you run the test? Then post it here. — Christopher Roscoe, Jul 19 '13 at 07:46
@ChristopherRoscoe : hi, when I compiled it, it gave me errors as above. Did you compile it successfully? Thanks — wlhee, Jul 19 '13 at 12:27

score 4 · Answer 1 · answered Jul 19 '13 at 13:01

I found out the problem, the test methods expects a exception. After I modified it as follows, it is working fine.

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassWithPrivate.class)
public class ClassWithPrivateTest {

   @Test
   public void testGetPrivateString() throws Exception {

     ClassWithPrivate spy = PowerMockito.spy(new ClassWithPrivate());

     PowerMockito.doReturn("Do").when(spy, method(ClassWithPrivate.class, "getPrivateStringWithArg", String.class)).withArguments(anyString());

   }

}

Partial Mock Private Method with PowerMock-Mockito

1 Answers1