def test_physical_type_instance_inequality(unit1, unit2):
"""
Test that `physical.PhysicalType` instances for units with different
dimensionality are considered unequal.
"""
physical_type1 = physical.PhysicalType(unit1, "ptype1")
physical_type2 = physical.PhysicalType(unit2, "ptype2")
assert (physical_type1 != physical_type2) is True
assert (physical_type1 == physical_type2) is False
def test_invalid_physical_types(invalid_input):
"""
Test that `PhysicalType` cannot be instantiated when one of the
supplied names is not a string, while making sure that the physical
type for the unit remains unknown.
"""
obscure_unit = u.s**87
with pytest.raises(ValueError):
physical.PhysicalType(obscure_unit, invalid_input)
assert obscure_unit.physical_type == "unknown"