CODEWITHSUNDEEP
javaunit-testingeasymock
VidyaSagar
VidyaSagar

Reputation: 1

Unexpected method call while doing the unit testing with EasyMock

I am testing mail functionality in my code with the UnitilsJUnit4 and EasyMock.

My code is like this..

public void prepare(MimeMessage mimeMessage) {
// some code ..
MimeMessageHelper message = new MimeMessageHelper( mimeMessage, true );
// some mail settings ..

}

when I am testing the method prepare, it is giving the below exception.. but the method it is showing below is from the Spring framework class.

java.lang.AssertionError: 
  Unexpected method call setContent(javax.mail.internet.MimeMultipart@6e616e61):
    setContent(javax.mail.internet.MimeMultipart@2dda2dda): expected: 1, actual: 0
    at $javax.mail.internet.MimeMessage$$EnhancerByCGLIB$$614de43f.setContent(<generated>)
    at org.springframework.mail.javamail.MimeMessageHelper.createMimeMultiparts(MimeMessageHelper.java:344)
    at org.springframework.mail.javamail.MimeMessageHelper.<init>(MimeMessageHelper.java:290)
    at org.springframework.mail.javamail.MimeMessageHelper.<init>(MimeMessageHelper.java:247)
    at org.springframework.mail.javamail.MimeMessageHelper.<init>(MimeMessageHelper.java:226)

Please help me to resolve the above issue.. how to test my method?

Upvotes: 0

Views: 6313

Answers (3)

HopefullyHelpful
HopefullyHelpful

Reputation: 341

I know this was written a long time ago, but I just encountered this exact same problem.

If you can mock the MimeMessageHelper in some form you can easily test the code. I did this by creating an interface that simply supplies back the MimeMessageHelper class and adding that as a dependency to the class I was testing.

Interface:

public interface MimeMessageHelperProvider {
    MimeMessageHelper getMimeMessageHelper(MimeMessage mimeMessage);
}

Implementation:

public class MimeMessageHelperProviderImpl implements MimeMessageHelperProvider {
    @Override
    public MimeMessageHelper getMimeMessageHelper(MimeMessage mimeMessage) {
        return new MimeMessageHelper(mimeMessage);
    }
}

Now you can wire in the MimeMessageHelperProvider and simply mock that interface to have it return you an instance you can verify against.

Upvotes: 2

jhericks
jhericks

Reputation: 5971

You need to mock the MimeMessageHelper. You can't inject it because it takes mimeMessage in the constructor. So to do this you need something like PowerMock.

From the documentation:

  1. Use the @RunWith(PowerMockRunner.class) annotation at the class-level of the test case.
  2. Use the @PrepareForTest(ClassThatCreatesTheNewInstance.class) annotation at the class-level of the test case.
  3. Use PowerMock.createMock(NewInstanceClass.class) to create a mock object of the class that should be constructed (let's call it mockObject).
  4. Use PowerMock.expectNew(NewInstanceClass.class).andReturn(mockObject) to expect a new construction of an object of type NewInstanceClass.class but instead return the mock object.
  5. Use PowerMock.replay(mockObject, NewInstanceClass.class) to change the mock object and class to replay mode, alternatively use the PowerMock.replayAll() method.
  6. Use PowerMock.verify(mockObject, NewInstanceClass.class) to change the mock object and class to verify mode, alternatively use the PowerMock.verifyAll() method.

Obviously, I don't really know what you're trying to test, but your test would look something like:

@RunWith(PowerMockRunner.class)
@PrepareForTest(MessagePreparer.class)
public class MessagePreparerTest {

  @Test
  public void testPrepare() {
    MimeMessage mockMessage = PowerMock.createMock(MimeMessage.class);
    MimeMessageHelper mockMessageHelper = PowerMock.createMock(MimeMessageHelper.class);
    PowerMock.expectNew(MimeMessageHelper.class, 
                        mockMessage, true).andReturn(mockMessageHelper);
    // ...set other expectations
    PowerMock.replay(mockMessage, mockMessageHelper, MimeMessageHelper.class);
    MessagePreparer messagePreparer = new MessagePreparer();
    messagePreparer.prepare(mockMessage);
    PowerMock.verify(mockMessage, mockMessageHelper, MimeMessageHelper.class);
  }
}

Upvotes: 1

Ryan Stewart
Ryan Stewart

Reputation: 128799

You seem to be mocking the wrong thing. You're mocking the Mail API when you should be mocking the Spring class, since that's what you interact with directly. The way you're doing it now, you're effectively testing the Spring class along with your own, which isn't really what you want.

Upvotes: 1

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