Mockito when method call not invoked, Verify return message "Wanted but not invoked,Actually, there were zero interactions with this mock" - mockito

Question

I am new to Mockito.
I have a problem.
I am trying to mock a class and call a method of that class with a hashmap which returns the same hashmap modified.
But i see that mocked method is not invoked. If i did verify i got the message as "Wanted but not invoked,Actually, there were zero interactions with this mock"
Here is my code
Class to test
public class ClassA{
private ClassB bb = new ClassB();
public boolean init() {
bb= new ClassB();
bb.init();
return true;
}
public void methodToTest(){
Map<String, Map<String, Integer>> hashmap= new LinkedHashMap<>();
hashmap = bb.method1(hashmap);
}
public ClassB getBB() {
return bb;
}
public void setBB(ClassB bb) {
this.bb= bb;
}
}
My Test class
#RunWith(PowerMockRunner.class)
public class TestClassA {
#Test
#PrepareForTest({Utilities.class, Logger.class, LoggerFactory.class})
public void getData() throws JsonProcessingException, JSONException {
Map<String, Map<String, Integer>> hashmap= new LinkedHashMap<>();
Map<String, Map<String, Integer>> newHashmap= new LinkedHashMap<>();
ClassA class2Test= new ClassA ();
ClassB mockClassB= Mockito.mock(ClassB.class);
PowerMockito.whenNew(ClassB.class).withAnyArguments().thenReturn(mockClassB);
Mockito.when(mockClassB.method1(hashmap)).thenReturn(newHashmap);
Mockito.verify(mockClassB).method1(hashmap);
class2Test.methodToTest();
}
}

Answer 1

I think you mixed a few things together.
With the refactored version you need to inject the mock for ClassB into ClassA (no need to use PowerMockito.whenNew).
Also note that the verifiy call has to be after the test method invocation.
#RunWith(PowerMockRunner.class)
public class SampleTest {
static class ClassB {
public Map<String, Map<String, Integer>> method1(Map<String, Map<String, Integer>> hashmap) {
return null;
}
}
static class ClassA {
private ClassB bb = new ClassB();
public void methodToTest() {
Map<String, Map<String, Integer>> hashmap = new LinkedHashMap<>();
hashmap = bb.method1(hashmap);
}
}
#Mock
ClassB bb;
#InjectMocks
ClassA class2Test;
#Test
public void test() throws Exception {
Map<String, Map<String, Integer>> hashmap = new LinkedHashMap<>();
Map<String, Map<String, Integer>> newHashmap = new LinkedHashMap<>();
Mockito.when(bb.method1(hashmap)).thenReturn(newHashmap);
class2Test.methodToTest();
Mockito.verify(bb).method1(hashmap);
}
}
For your old code the test would look something like this, but if you can use the version above.
The #PrepareForTest has to contain the class where the byte code should be manipulated, in this case ClassA.
#Test
#PrepareForTest(ClassA.class)
public void test() throws Exception {
Map<String, Map<String, Integer>> hashmap = new LinkedHashMap<>();
Map<String, Map<String, Integer>> newHashmap = new LinkedHashMap<>();
ClassB bb = Mockito.mock(ClassB.class);
Mockito.when(bb.method1(hashmap)).thenReturn(newHashmap);
PowerMockito.whenNew(ClassB.class).withAnyArguments().thenReturn(bb);
ClassA class2Test = new ClassA();
class2Test.methodToTest();
Mockito.verify(bb).method1(hashmap);
}