Java – exception: mockito wants but is not called, but actually interacts with zero of this simulation

I have an interface

Interface MyInterface {
  myMethodToBeVerified (String,String);
}

The implementation interface is

class MyClassToBeTested implements MyInterface {
   myMethodToBeVerified(String,String) {
    …….
   }
}

I have another class

class MyClass {
    MyInterface myObj = new MyClassToBeTested();
    public void abc(){
         myObj.myMethodToBeVerified (new String(“a”),new String(“b”));
    }

}

I'm writing JUnit for MyClass I've done it

class MyClassTest {
    MyClass myClass = new MyClass();

    @Mock
    MyInterface myInterface;

    testAbc(){
         myClass.abc();
         verify(myInterface).myMethodToBeVerified(new String(“a”),new String(“b”));
    }
}

But I got what mockito wanted, but it was not called. In fact, the interaction with the simulation was zero when verifying the call

Someone can propose some solutions

Solution

You need to inject simulation into the class you test You are currently interacting with real objects, not simulated objects You can fix the code in the following ways:

void testAbc(){
     myClass.myObj = myInteface;
     myClass.abc();
     verify(myInterface).myMethodToBeVerified(new String(“a”),new String(“b”));
}

Although extracting all the initialization code into @ before would be a wiser choice

@Before
void setUp(){
     myClass = new myClass();
     myClass.myObj = myInteface;
}

@Test
void testAbc(){
     myClass.abc();
     verify(myInterface).myMethodToBeVerified(new String(“a”),new String(“b”));
}