test_read_only_quantity.py

from barril.units import ObtainQuantity, Quantity, UnitDatabase
import pytest


def testReadOnlyQuantity(unit_database_empty):
    unit_database = unit_database_empty

    unit_database.AddUnitBase("length", "meters", "m")
    unit_database.AddUnit("length", "centimeters", "cm", "%f * 100.0", "%f / 100.0")
    unit_database.AddCategory("length", "length")

    read_only_quantity = ObtainQuantity("m", "length")
    with pytest.raises(AttributeError):
        read_only_quantity.SetUnit("cm")

    # When creating a copy of a read only quantity we'll make it not read only anymore!
    copy = read_only_quantity.MakeCopy(Quantity)
    assert copy.GetUnitDatabase() is unit_database


def testMultiplyReadOnlyQuantity():
    """
    Raising an Error when Geometry quantity is read only (...)

    This test simulates the conditions of the bug report. This bug has been fixed before I try
    to reproduce here.
    """
    unit_database = UnitDatabase.GetSingleton()

    meters = ObtainQuantity("m", "length")

    r_quantity, _value = unit_database.Multiply(meters, meters, 1.0, 1.0)
    assert r_quantity.GetUnit() == "m2"