Resolve traceback error when using variables in template triggers

[ehendrix23]

Proposed change

Fix traceback error NoneType can't be used in await expression when using variables in template triggers.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Errors while using trigger variables with trigger-based template entities. #72434
• This PR is related to issue:
• Link to documentation pull request:

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• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
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• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

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[probot-home-assistant]

Hey there @PhracturedBlue, @tetienne, @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (template) you are listed as a code owner for? Thanks!
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[ehendrix23]

Just doing a quick check on status. I have not seen these errors occur at all within my installation after implementing this fix and everything has been working fine related to it.

[emontnemery]

The problem is caused by a regression introduced by #68275
While this PR hides the problem in the template integration, the same problem exists also in websocket_api etc.

Instead of this, we should fix the _trigger_action_wrapper which was introduced by https://github.com/home-assistant/core/pull/68275 to handle either regular functions or coroutine functions, following this pattern:

core/homeassistant/util/logging.py

Lines 133 to 174 in 1a7784e

	def catch_log_exception(
	func: Callable[..., Any], format_err: Callable[..., Any]
	) -> Callable[..., None] | Callable[..., Coroutine[Any, Any, None]]:
	"""Decorate a function func to catch and log exceptions.
	If func is a coroutine function, a coroutine function will be returned.
	If func is a callback, a callback will be returned.
	"""
	# Check for partials to properly determine if coroutine function
	check_func = func
	while isinstance(check_func, partial):
	check_func = check_func.func
	wrapper_func: Callable[..., None] | Callable[..., Coroutine[Any, Any, None]]
	if asyncio.iscoroutinefunction(check_func):
	async_func = cast(Callable[..., Coroutine[Any, Any, None]], func)
	@wraps(async_func)
	async def async_wrapper(*args: Any) -> None:
	"""Catch and log exception."""
	try:
	await async_func(*args)
	except Exception: # pylint: disable=broad-except
	log_exception(format_err, *args)
	wrapper_func = async_wrapper
	else:
	@wraps(func)
	def wrapper(*args: Any) -> None:
	"""Catch and log exception."""
	try:
	func(*args)
	except Exception: # pylint: disable=broad-except
	log_exception(format_err, *args)
	if is_callback(check_func):
	wrapper = callback(wrapper)
	wrapper_func = wrapper
	return wrapper_func

[ehendrix23]

I've reverted the change I initially did within the template and updated _trigger_action_wrapper instead using the example provided.
Ran test on everything under components/template and everything under helpers/test_trigger without issues.
Updated my local copy for home assistant and no errors, also no errors as reported originally.

Let me know if these changes look good or further updates required. :-)

[emontnemery]

Thanks @ehendrix23 !

Unfortunately, the more complicated solution I linked to is needed to avoid returning a coroutine function when wrapping a regular function. I updated the PR accordingly + added a test.

It would be helpful if you can verify this also solves your problem.

[balloob]

Not needed if you use inspect.iscoroutinefunction

[emontnemery]

While it's not needed for inspect.iscoroutinefunction, it's needed for is_callback.
If we teach is_callback about unwinding partials we can indeed drop it, that's for another PR though.

[ehendrix23]

Thanks. I didn't think the more complex one was required but I guess I was wrong. :-)

Tested on my local instance and issue is not occurring. So looks like this is working.

Saw the comment from balloob. And you acknowledging but not sure if anything further is required as it looks like there was a force push but I don't see any difference in that section. :-)

[emontnemery]

@ehendrix23 right, I first implemented @balloob's suggestion, then I realized we need the unwinding also for is_partial so I reverted it. Sorry about the force push, I should have done a revert commit instead.