url() does not return a ParseResult when using empty string default value

[jnm]

https://django-environ.readthedocs.io/en/latest/api.html#environ.Env.url indicates that url() returns a urllib.parse.ParseResult, but sometimes it can return a str:

Python 3.10.5 (main, Jun 11 2022, 16:53:24) [GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import environ
>>> e = environ.Env()
>>> e.url('UNSET_VAR', '')
''

Contrast with the behavior for an empty (but set) environment variable:

>>> e.url('EMPTY_VAR')
ParseResult(scheme='', netloc='', path='', params='', query='', fragment='')

Usually, I want to call geturl() immediately on the result of url(), and it would be convenient if this worked consistently instead of sometimes raising AttributeError: 'str' object has no attribute 'geturl'.

url() does use parse_default=True:

django-environ/environ/environ.py

Lines 292 to 301 in 7720a49

	def url(self, var, default=NOTSET):
	"""
	:rtype: urllib.parse.ParseResult
	"""
	return self.get_value(
	var,
	cast=urlparse,
	default=default,
	parse_default=True
	)

However, when default coerces to False, it is not parsed:

django-environ/environ/environ.py

Lines 429 to 430 in 7720a49

	if value != default or (parse_default and value):
	value = self.parse_value(value, cast)

I see that the and value logic was added as a fix for #44, but I wonder if we could check for and value is not None instead. I'll try this and see if all tests continue to pass.

[sergeyklay]

Fixed in #405. Thank you for the report!