Pylance doesn't recognise attributes obtained from `fields`

[my1e5]

Consider this MRE

from attrs import define, fields

@define
class A:
    foo: int
    bar: float

f = fields(A)

print(f.foo)

Attribute(name='foo', default=NOTHING, validator=None, repr=True, eq=True, eq_key=None, order=True, order_key=None, hash=None, init=True, metadata=mappingproxy({}), type=<class 'int'>, converter=None, kw_only=False, inherited=False, on_setattr=None, alias='foo')

This all works fine.

The only thing that isn't working perfectly is Pylance doesn't seem to properly recognise this. It highlights the attribute in white and incorrect hover text is provided.

Looking at the types, I found

print(type(f))

<class 'AAttributes'>

But I couldn't find any reference to AAttributes in the codebase.

My question is, is there something that attrs needs to do to make Pylance work here? Or is this a bug/limitation with Pylance and I should open a ticket with them to get support for this?

Thanks.

[hynek]

attrs creates on-demand classes for attributes for each class:

attrs/src/attr/_make.py

Lines 246 to 270 in 13e9a6a

	def _make_attr_tuple_class(cls_name, attr_names):
	"""
	Create a tuple subclass to hold `Attribute`s for an `attrs` class.
	The subclass is a bare tuple with properties for names.
	class MyClassAttributes(tuple):
	__slots__ = ()
	x = property(itemgetter(0))
	"""
	attr_class_name = f"{cls_name}Attributes"
	attr_class_template = [
	f"class {attr_class_name}(tuple):",
	" __slots__ = ()",
	]
	if attr_names:
	for i, attr_name in enumerate(attr_names):
	attr_class_template.append(
	f" {attr_name} = _attrs_property(_attrs_itemgetter({i}))"
	)
	else:
	attr_class_template.append(" pass")
	globs = {"_attrs_itemgetter": itemgetter, "_attrs_property": property}
	_compile_and_eval("\n".join(attr_class_template), globs)
	return globs[attr_class_name]

Unfortunately, Pyright is not keen on implementing non-PEP features.