Adds mypy annotations for templatetags

[mouse-reeve]

Description

I figured I'd try and get used to typing, so I added some typing.

One thing I haven't figured out is how to handle definitions that take *args and can be called with miscellaneous arguments (maybe you know, @jderuiter?).

• Related Issue Consider adding types via mypy #2722

What type of Pull Request is this?

• Bug Fix
• Enhancement
• Plumbing / Internals / Dependencies
• Refactor

Does this PR change settings or dependencies, or break something?

• This PR changes or adds default settings, configuration, or .env values
• This PR changes or adds dependencies
• This PR introduces other breaking changes

Details of breaking or configuration changes (if any of above checked)

Documentation

• New or amended documentation will be required if this PR is merged
• I have created a matching pull request in the Documentation repository
• I intend to create a matching pull request in the Documentation repository after this PR is merged

Tests

• My changes do not need new tests
• All tests I have added are passing
• I have written tests but need help to make them pass
• I have not written tests and need help to write them

[mouse-reeve]

@bookwyrm-social/code-review would be great, I am new to using type annotations

[jderuiter]

One thing I haven't figured out is how to handle definitions that take *args and can be called with miscellaneous arguments (maybe you know, @jderuiter?).

Do you maybe have an example of this?

[dato]

One thing I haven't figured out is how to handle definitions that take *args and can be called with miscellaneous arguments (maybe you know, @jderuiter?).

Do you maybe have an example of this?

I think this is about utils.cache.get_or_set(), which receives a callable, and then the arguments for that callable:

bookwyrm/bookwyrm/utils/cache.py

Lines 7 to 18 in af5f71f

	def get_or_set(
	cache_key: str,
	function: Callable[..., Any],
	*args: Tuple[Any, ...],
	timeout: Union[float, None] = None
	) -> Any:
	"""Django's built-in get_or_set isn't cutting it"""
	value = cache.get(cache_key)
	if value is None:
	value = function(*args)
	cache.set(cache_key, value, timeout=timeout)
	return value

This can be typed more narrowly using typing.ParamSpec:

from typing import Callable, Optional, ParamSpec, TypeVar

Args = ParamSpec("Args")
Ret = TypeVar("Ret")

def get_or_set(
    cache_key: str,
    function: Callable[Args, Ret],
    *args: Args.args,
    timeout: Optional[float] = None
) -> Ret:
    ...

@mouse-reeve: you can pull this fix (and a couple other minor improvements) from this branch in my repo: mypy...dato:bookwyrm:push-ovrtyrmwkoxu. (I can also push here directly if you prefer!) With these three commits, the arg-type and misc disables are no longer needed.

[mouse-reeve]

thank you! I think ... was the piece I was missing