Dotted path resolution and tests

gistfile1.py

def get_callable_name(func):
    """
    Returns the best available display name for the given function/callable.

    :rtype: str
    """

    # the easy case (on Python 3.3+)
    if hasattr(func, '__qualname__'):
        return func.__qualname__

    # class methods, bound and unbound methods
    f_self = getattr(func, '__self__', None) or getattr(func, 'im_self', None)
    if f_self and hasattr(func, '__name__'):
        f_class = f_self if isinstance(f_self, type) else f_self.__class__
    else:
        f_class = getattr(func, 'im_class', None)

    if f_class and hasattr(func, '__name__'):
        return '%s.%s' % (f_class.__name__, func.__name__)

    # class or class instance
    if hasattr(func, '__call__'):
        # class
        if hasattr(func, '__name__'):
            return func.__name__

        # instance of a class with a __call__ method
        return func.__class__.__name__

    raise TypeError('Unable to determine a name for %r -- maybe it is not a callable?' % func)


def obj_to_ref(obj):
    """
    Returns the path to the given object.

    :rtype: str
    """

    try:
        ref = '%s:%s' % (obj.__module__, get_callable_name(obj))
        obj2 = ref_to_obj(ref)
        if obj != obj2:
            raise ValueError
    except Exception:
        raise ValueError('Cannot determine the reference to %r' % obj)

    return ref

gistfile2.py

class TestObjToRef(object):
    @pytest.mark.parametrize('input', [partial(DummyClass.meth)], ids=['partial/bound method'])
    def test_no_ref_found(self, input):
        exc = pytest.raises(ValueError, obj_to_ref, input)
        assert 'Cannot determine the reference to ' in str(exc.value)

    @pytest.mark.parametrize('input,expected', [
        pytest.mark.skipif(sys.version_info[:2] == (3, 2), reason="Unbound methods can't be resolved on Python 3.2")(
            (DummyClass.meth, 'tests.test_util:DummyClass.meth')
        ),
        (DummyClass.classmeth, 'tests.test_util:DummyClass.classmeth'),
        pytest.mark.skipif(sys.version_info < (3, 3), reason="Requires __qualname__ (Python 3.3+)")(
            (DummyClass.InnerDummyClass.innerclassmeth, 'tests.test_util:DummyClass.InnerDummyClass.innerclassmeth')
        ),
        pytest.mark.skipif(sys.version_info < (3, 3), reason="Requires __qualname__ (Python 3.3+)")(
            (DummyClass.staticmeth, 'tests.test_util:DummyClass.staticmeth')
        ),
        (timedelta, 'datetime:timedelta'),
    ], ids=['unbound method', 'class method', 'inner class method', 'static method', 'timedelta'])
    def test_valid_refs(self, input, expected):
        assert obj_to_ref(input) == expected