Conflict between Jacoco and Jmockit while running Unit Tests which uses Jmockit for Mocking.

[Praveen S P]

Hi Everyone ,

I m using Jacoco (Version : 0.7.9)  for Code Coverage and Jmockit (Version :1.28) for Mocking purpose while running my unit test cases. But is see a peculiar exception when execute my test cases with this combination of Jacoco and Jmockit.

 

Here is the Exception :

"java.lang.UnsupportedOperationException: class redefinition failed: attempted to change the schema (add/remove fields)".

I have used jmockit for mocking in my unti testcases. I see this exception in only those test cases where Jmockit mocking being used. Other Test cases which does not use any jmockit mocking are going fine.Hence this is a issue between jmockit and jacoco. I was trying to solve this issue for long time. I tried changing maven surefire plugin version, and  i saw that in this link "http://www.jacoco.org/jacoco/trunk/doc/changes.html" that this same issue has been solved in 0.7.3 .So i downgraded the version from 0.7.9 to 0.7.3 .But this also could not solve the issue . 

As per my understanding , there is a conflict when we use jacoco and jmockit simultaneously . So i want to know how to solve this issue and what is the solution for the conflict between jacoco and Jmockit.

can anyone help me on this ..Please..!! 

Thank You

-Praveen

[Evgeny Mandrikov]

Hi,

To speedup understanding of your issue, please provide minimalistic example of project demonstrating this.

Regards,

Evgeny

[Praveen S P]

Hi Evgeny,

Thanks for the quick reply

To explain further regarding the above issue , here is the small example.

These are two public java classes .

Class A:

public class A(){

      int a;

      public A(){}

      public int Method1(){

               a=10;

               return a;

         }

}

Class B:

public class B(){

       int b;

       private A object_of_a;

       public B(){}

       

       public int method2(){

                int c= object_of_a.Method1();

                b=b+c;

                return c;

       }

}

This is a Unit Test Class which is written for Class B. In this unit test case i m using Jmockit for mocking some of the methods.  

In the Below Test Case i m mocking the method Method1() of Class A using Jmockit and I use Jacoco agent to run the test case.

import org.testng.annotations.Test;

import org.junit.runner.RunWith;

import mockit.MockUp;

import mockit.Mock;

@Test

@RunWith(JMockit.class)

public class Test_B(){

       public Test_B(){}

       

       @BeforeClass

        public void setup() throws Exception {

        }

        @Test

         public void test_method2(){

                     

                     new MockUp(A){        < -- 10 ( Here i get Exception)

                          @Mock

                          public int Method1(){

                                   return 1290;

                           }   

                     };

                    

                    B b = new B();

                    int res = b.method2();

         }

}

Now , I execute my Test Case Test_B(). For this i use jacoco - maven -plugin 0.7.9 and Jmockit version 1.28.

When i execute the testcase with these two configuarations , My testcase is getting failed at Line 10 which is mentioned above with the exception  -- > "java.lang.UnsupportedOperationException: class redefinition failed: attempted to change the schema (add/remove fields)".

And,if i remove Jacoco plugin and just execute the test case as a normal test case without any jacoco agent in the command and using just jmockit version, It's works fine without any exception. So i m facing this issue when both jacoco and jmockit are used together.

I want to know how to solve this conflct or is this a bug in Jacoco version 0.7.9 which is not working fine with other plugins like Jmockit.

Thanks,

-Praveen

[Evgeny Mandrikov]

Sorry, but what you provided is not even compilable ("public class A(){" - is not a valid class declaration) and contains strange mix of TestNG and JUnit annotations.

As a more reliable way of transfer please provide an archive that contains example that is complete (including pom.xml), compilable and runnable without exceptions without JaCoCo.