def test_populate_defaults(self):
class Foo(dict):
field = Field(default="foo")
foo = Foo()
populate_defaults(foo)
self.assertEqual("foo", foo.field)
self.assertEqual("foo", foo["field"])
def test_serialize_none_value(self):
class Model(dict):
field = Field(serialize=lambda x, y: str(y), default=None)
model = Model()
populate_defaults(model)
self.assertEqual(None, model["field"])
self.assertEqual(None, model.field)
# but falsy values should still be serialized...
model.field = 0
self.assertEqual('0', model["field"])
def __new__(cls, *args, **kwargs):
# caching fields and required fields on the model
# so we don't have to discover every time.
if not hasattr(cls, "_fields"):
fields = []
required_fields = []
for field_name, field in get_all_fields(cls):
fields.append(field_name)
if field.required:
required_fields.append(field_name)
cls._fields = set(fields)
cls._required_fields = set(required_fields)
instance = super(Model, cls).__new__(cls)
instance._data = {}
populate_defaults(instance)
return instance
