def test_convert_weight_to_ml(self):
"""Convert units of weight to milliliters.
"""
# Two foods with very different densities
honey = Food.objects.get(name='honey')
paprika = Food.objects.get(name='paprika')
# Two units of weight
gram = Unit.objects.get(name='gram')
ounce = Unit.objects.get(name='ounce')
g_per_oz = Equivalence.objects.get(unit=ounce, to_unit=gram).to_quantity
# Convert units of weight into milliliters
# Without food, assume 1.0 g/ml
self.failUnlessEqual(to_ml(gram), 1.0)
self.failUnlessEqual(to_ml(ounce), g_per_oz)
# With food, use its density
self.failUnlessEqual(to_ml(gram, honey), 1.0 / honey.grams_per_ml)
self.failUnlessEqual(to_ml(gram, paprika), 1.0 / paprika.grams_per_ml)
self.failUnlessEqual(to_ml(ounce, honey), g_per_oz / honey.grams_per_ml)
self.failUnlessEqual(to_ml(ounce, paprika), g_per_oz / paprika.grams_per_ml)
def test_convert_volume_to_ml(self):
"""Convert units of volume to milliliters.
"""
cup = Unit.objects.get(name='cup')
ml_per_cup = convert_unit('cup', 'milliliter')
self.failUnlessEqual(to_ml(cup), ml_per_cup)