Question

The following code results in org.mockito.exceptions.misusing.MissingMethodInvocationException:

Level level = mock(Level.class);
IOException ioException = new IOException("test");
when(level.getSyslogEquivalent()).thenThrow(ioException);

Answer 1

Did you check the MissingMethodInvocationException exception message ?

It says :

when() requires an argument which has to be 'a method call on a mock'.
For example:
    when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
2. inside when() you don't call method on mock but on some other object.
3. the parent of the mocked class is not public.
   It is a limitation of the mock engine.

Either the class Level is final (clearly not as I remember extending this class) or the getSyslogEquivalent is final (best guess).

So you should either revise your design or test design or maybe try Powermock, which offers final class/method mocking.

Hope that helps