Add bool template filter and function

[pyos]

Proposed change

Add a new template filter (and a matching function) bool, analogous to the existing float, int, as_timestamp, etc. The filter returns true for "true", "yes", "on", "enable", "1", boolean true, and non-zero numbers; and false for "false", "no", "off", "disable", "0", boolean false, and zero. In other cases an error is thrown or a default is returned, if specified.

The motivation for this are binary sensors and similar entities. If they were only on or off, an is_state(..., "on") would be sufficient; however, they could also be unknown or unavailable, and handling that currently requires long if-else chains. For numeric sensors we can do states("sensor.temperature") | int(none) to get either the value or none, and this PR makes something like states("binary_sensor.door") | bool(none) possible as well. This synergizes with the existing iif filter: states("binary_sensor.door") | bool(none) | iif("open", "closed", "sensor died").

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)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• Link to documentation pull request: Document int and boolean template filters home-assistant.io#23221

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[emontnemery]

Suggestions for fixing the typing.

These changes are also needed:

diff --git a/homeassistant/helpers/template.py b/homeassistant/helpers/template.py
index 55bde9bbb5..5fce146e3b 100644
--- a/homeassistant/helpers/template.py
+++ b/homeassistant/helpers/template.py
@@ -19,7 +19,7 @@ import re
 import statistics
 from struct import error as StructError, pack, unpack_from
 import sys
-from typing import Any, cast
+from typing import Any, NoReturn, TypeVar, cast, overload
 from urllib.parse import urlencode as urllib_urlencode
 import weakref

@@ -92,6 +92,8 @@ _COLLECTABLE_STATE_ATTRIBUTES = {
     "name",
 }

+_T = TypeVar("_T")
+
 ALL_STATES_RATE_LIMIT = timedelta(minutes=1)
 DOMAIN_STATES_RATE_LIMIT = timedelta(seconds=1)

@@ -1375,7 +1389,7 @@ def utcnow(hass: HomeAssistant) -> datetime:
     return dt_util.utcnow()


-def raise_no_default(function, value):
+def raise_no_default(function: str, value: Any) -> NoReturn:
     """Log warning if no default is specified."""
     template, action = template_cv.get() or ("", "rendering or compiling")
     raise ValueError(

[emontnemery]

Thanks @pyos, this is a great first contribution to the project 🚀

[frenck]

This looks great! Many will love this 👍