Mypy misc error using new Workflow/TemplateSet decorators

[alicederyn]

Pre-bug-report checklist

1. This bug can be reproduced using pure Argo YAML

• Yes 👉 Please report a bug to the Argo Workflows GitHub 👈
• No

If yes, it is more likely to be an Argo bug unrelated to Hera. Please double check before submitting an issue to Hera.

2. I have searched for existing issues

• Yes

3. This bug occurs in Hera when...

• exporting to YAML
• submitting to Argo
• running on Argo with the Hera runner
• other: Type checking

Bug report

Describe the bug
A clear and concise description of what the bug is:

Mypy is raising an error on code using the new Workflow/TemplateSet decorators:

Error log if applicable:

error: Attribute function "script" with type "Callable[[DefaultNamedArg(Any, 'volumes'), DefaultNamedArg(Any, 'volume_devices'), DefaultNamedArg(Any, 'volume_mounts'), DefaultNamedArg(Any, 'resources'), DefaultNamedArg(Any, 'metrics'), DefaultNamedArg(Any, 'active_deadline_seconds'), DefaultNamedArg(Any, 'affinity'), DefaultNamedArg(Any, 'archive_location'), DefaultNamedArg(Any, 'automount_service_account_token'), DefaultNamedArg(Any, 'daemon'), DefaultNamedArg(Any, 'executor'), DefaultNamedArg(Any, 'fail_fast'), DefaultNamedArg(Any, 'host_aliases'), DefaultNamedArg(Any, 'init_containers'), DefaultNamedArg(Any, 'memoize'), DefaultNamedArg(Any, 'annotations'), DefaultNamedArg(Any, 'labels'), DefaultNamedArg(Any, 'name'), DefaultNamedArg(Any, 'node_selector'), DefaultNamedArg(Any, 'parallelism'), DefaultNamedArg(Any, 'http'), DefaultNamedArg(Any, 'plugin'), DefaultNamedArg(Any, 'pod_spec_patch'), DefaultNamedArg(Any, 'priority'), DefaultNamedArg(Any, 'priority_class_name'), DefaultNamedArg(Any, 'retry_strategy'), DefaultNamedArg(Any, 'scheduler_name'), DefaultNamedArg(Any, 'pod_security_context'), DefaultNamedArg(Any, 'service_account_name'), DefaultNamedArg(Any, 'sidecars'), DefaultNamedArg(Any, 'synchronization'), DefaultNamedArg(Any, 'timeout'), DefaultNamedArg(Any, 'tolerations'), DefaultNamedArg(Any, 'image'), DefaultNamedArg(Any, 'image_pull_policy'), DefaultNamedArg(Any, 'liveness_probe'), DefaultNamedArg(Any, 'ports'), DefaultNamedArg(Any, 'readiness_probe'), DefaultNamedArg(Any, 'startup_probe'), DefaultNamedArg(Any, 'stdin'), DefaultNamedArg(Any, 'stdin_once'), DefaultNamedArg(Any, 'termination_message_path'), DefaultNamedArg(Any, 'termination_message_policy'), DefaultNamedArg(Any, 'tty'), DefaultNamedArg(Any, 'inputs'), DefaultNamedArg(Any, 'outputs'), DefaultNamedArg(Any, 'env'), DefaultNamedArg(Any, 'env_from'), DefaultNamedArg(Any, 'container_name'), DefaultNamedArg(Any, 'args'), DefaultNamedArg(Any, 'command'), DefaultNamedArg(Any, 'lifecycle'), DefaultNamedArg(Any, 'security_context'), DefaultNamedArg(Any, 'source'), DefaultNamedArg(Any, 'working_dir'), DefaultNamedArg(Any, 'add_cwd_to_sys_path'), DefaultNamedArg(Any, 'constructor'), KwArg(Any)], Callable[[Callable[FuncIns, FuncR]], Callable[FuncIns, FuncR]]]" does not accept self argument  [misc]

To Reproduce
Full Hera code to reproduce the bug:

from hera.shared import global_config
from hera.workflows import Input, Output, TemplateSet

global_config.experimental_features["decorator_syntax"] = True

template_set = TemplateSet()
@template_set.script()
def simple_script(_: Input) -> Output:
    return Output()

Expected behavior
A clear and concise description of what you expected to happen:

No mypy errors.

Environment

• Hera Version: 5.16.2
• Python Version: 3.11.8
• Argo Version: N/A

Additional context
I believe the issue is that the type hints being added by the _add_type_hints decorator do not include a self parameter, only the kwargs copied from the PydanticKwargs param spec:

hera/src/hera/workflows/_meta_mixins.py

Lines 478 to 491 in a50ba23

	def _add_type_hints(
	_pydantic_obj: Callable[PydanticKwargs, PydanticCls],
	) -> Callable[
	...,
	Callable[
	PydanticKwargs, # this adds type hints to the underlying *library* function kwargs
	Callable[ # we will return a function that is a decorator
	[Callable[FuncIns, FuncR]], # taking underlying *user* function
	Callable[FuncIns, FuncR], # and returning it
	],
	],
	]:
	"""Adds type hints to the decorated function."""
	return lambda func: func