must_exist=False raise Validation error on attribute presenting in config file #1286
Description
I have set up two validators like this:
def validators(self):
return [
Validator(
'config.len_delta',
is_type_of=int,
must_exist=False,
default=2,
),
Validator(
'config.expire',
is_type_of=int,
must_exist=False,
default=2,
),
]
The error message I got was the config.expire cannot exist in env test.
The error was raised from here:
# is name required but not exists?
if self.must_exist is True and value is empty:
_message = self.messages['must_exist_true'].format(name=name, env=env)
raise ValidationError(_message, details=[(self, _message)])
# Does this code not indicate that name is not required but name has a value?
# If it is not required, it cannot have a value? Is this really the intention?
if self.must_exist is False and value is not empty:
_message = self.messages['must_exist_false'].format(name=name, env=env)
raise ValidationError(_message, details=[(self, _message)])
And I read from validator's reference that:
must_exist is alias to required requirement. (executed after when)
I had the same interpretation as it was described in the API reference.
Through the above setting I was trying to convey that the attribute does not have to be present; if it was not present, it carries a default value of 2.
In short, does must_exist=False = "not required" = "optional", or must_exist=False = "Cannot have it in config" ?