How to mock EntityManager? [closed]

Question

I suggest to use Mockito Framework it is very easy to use and understand.

@Mock
private EntityManager entityManager;

If you want to use any method that belongs to entityManager, you should call.

Mockito.when(METHOD_EXPECTED_TO_BE_CALLED).thenReturn(AnyObjectoftheReturnType);

When you run your test, any call previosly declared in the Mockito.when for the EntityManager will return the value put in the declaration..

Read full documentation here.

https://static.javadoc.io/org.mockito/mockito-core/2.12.0/org/mockito/Mockito.html#stubbing