def test_ref_unit(self):
cup = CustomUnitPolicy(
[ScaleUnitConversion(Unit('km'), Unit('m'), 1000)])
assert cup.ref_unit(Unit('km')) == Unit('m')
assert cup.ref_unit(Unit('m')) == Unit('m')
with raises(ValueError):
cup.ref_unit(Unit('furlong')) # unit doesn't exist
def test_duplicate_overwrite(self):
cup = CustomUnitPolicy([
ScaleUnitConversion(Unit('km'), Unit('m'), 1000),
ScaleUnitConversion(Unit('km'), Unit('mm'), 1000000)
],
duplicates='overwrite')
assert cup.ref_unit(Unit('km')) == Unit('mm')