Check the Java API for List.
get(int index) method is declared to throw only the
IndexOutOfBoundException which extends
You are trying to tell Mockito to throw an exception
SomeException() that is not valid to be thrown by that particular method call.
To clarify further.
The List interface does not provide for a checked Exception to be thrown from the
get(int index) method and that is why Mockito is failing.
When you create the mocked List, Mockito will use the definition of List.class to creates its mock.
The behavior you are specifying with the
when(list.get(0)).thenThrow(new SomeException()) doesn’t match the method signature in List API, because
get(int index) method does not throw
SomeException() so Mockito fails.
If you really want to do this, then have Mockito throw a
new RuntimeException() or even better throw a
new ArrayIndexOutOfBoundsException() since the API specifies that that is the only valid Exception to be thrown.