autodoc_class_signature = "separated" cause a warning for enum with no __init__

[trim21]

Describe the bug

autodoc_class_signature = "separated" option will cause class without __init__ raise a warning and can't build with -W

How to Reproduce

use this repo: https://github.com/trim21/sphinx-autodoc_class_signature-bug

git cl https://github.com/trim21/sphinx-autodoc_class_signature-bug sphinx-autodoc_class_signature-bug
cd sphinx-autodoc_class_signature-bug
pip install -e .
sphinx-build -W docs dist

Environment Information

Platform:              win32; (Windows-10-10.0.19045-SP0)
Python version:        3.10.11 (tags/v3.10.11:7d4cc5a, Apr  5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)])
Python implementation: CPython
Sphinx version:        7.3.2
Docutils version:      0.21.2
Jinja2 version:        3.1.4
Pygments version:      2.18.0

Sphinx extensions

extensions = [
    "sphinx.ext.autodoc",
    "sphinx.ext.viewcode",
    "sphinx.ext.napoleon",
]

Additional context

No response

[electric-coder]

Your repo doesn't have any Python class and no Enum as said in the title. This bug report is missing a minimal reproducer.

[trim21]

Your repo doesn't have any Python class and no Enum as said in the title. This bug report is missing a minimal reproducer.

Which repo are you talking about?

https://github.com/trim21/sphinx-autodoc_class_signature-bug/blob/ee160815ed1c6217e1e4b9751c7d362453ee4c8a/lib/__init__.py#L4

lib/__init__.py

import enum


class Status(str, enum.Enum):
    """enum for status"""

[picnixz]

I can confirm the bug but I'm not sure if it's a bug because of the .. autoclass directive or not... Without the directive and by using :members: for .. automodule, the enumeration is being shown normally but using autoclass on the enumeration, it appears that there is an issue...

I can try to fix it but I don't like specializing the behaviours for enums in general because it's an API that is constantly changing... I'll try to see what I can do.

[trim21]

interesting, now I can't re-produce this...

[trim21]

OK, I'm guessing this only happed on old version of python. I can reproduce this with py 3.9 but not 3.12

[picnixz]

Oh yes, I was using the same version as you (3.10) and could confirm the bug. That's why I said I hate working with the enum API since it changes every version...

[trim21]

I more generic way could be make :exclude-members: __init__ work? I guess?

I don't know how sphinx works internally...

[trim21]

Normal class with __new__ only doesn't have this problem...

[picnixz]

The exclude-members wouldn't work because we are always picking all members before excluding them later. The rationale is because the filtering logic can be changed by the user after. The flow is more or less:

• Pick everything.
• Filter when needed.
• Ask extensions if this should really be filtered.
• Do your things.

However, the warnings happens before the exclusion is being made (it's trying to pick up every possible members).

[trim21]

thanks for your answer.

[picnixz]

I've found the issue:

sphinx/sphinx/ext/autodoc/__init__.py

Lines 1490 to 1498 in 9cc0ea1

	if self.config.autodoc_class_signature == 'separated':
	self.options = self.options.copy()
	# show __init__() method
	if self.options.special_members is None:
	self.options['special-members'] = ['__new__', '__init__']
	else:
	self.options.special_members.append('__new__')
	self.options.special_members.append('__init__')

It appears we are forcibly assuming that __new__ and __init__ exist, which may not necessarily be the case and you get the warning here:

sphinx/sphinx/ext/autodoc/__init__.py

Lines 1755 to 1760 in 9cc0ea1

	for name in self.options.members:
	if name in members:
	selected.append(members[name])
	else:
	logger.warning(__('missing attribute %s in object %s'),
	name, self.fullname, type='autodoc')

So, I should add some if-logic for this warning if the __new__ and __init__ are missing but I won't have much time today.

[trim21]

I currently just use workaround with adding :members: