Fix incorrect type hint in config_per_platform helper (#63890)

* Adjust base helper

* Filter type is not None in mailbox

* Filter empty platforms in device_tracker

* Filter out empty platform in notify

* Filter out empty platform in entity_component

Co-authored-by: epenet <epenet@users.noreply.github.com>

homeassistant/components/device_tracker/legacy.py

@@ -291,6 +291,7 @@ async def async_extract_config(
         *(
             async_create_platform_type(hass, config, p_type, p_config)
             for p_type, p_config in config_per_platform(config, DOMAIN)
+            if p_type is not None
         )
     ):
         if platform is None:

homeassistant/components/mailbox/__init__.py

@@ -86,6 +86,7 @@ async def async_setup(hass, config):
     setup_tasks = [
         asyncio.create_task(async_setup_platform(p_type, p_config))
         for p_type, p_config in config_per_platform(config, DOMAIN)
+        if p_type is not None
     ]
 
     if setup_tasks:

homeassistant/components/notify/legacy.py

@@ -102,6 +102,7 @@ async def async_setup_legacy(hass: HomeAssistant, config: ConfigType) -> None:
     setup_tasks = [
         asyncio.create_task(async_setup_platform(integration_name, p_config))
         for integration_name, p_config in config_per_platform(config, DOMAIN)
+        if integration_name is not None
     ]
 
     if setup_tasks:

homeassistant/helpers/__init__.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 
 from collections.abc import Iterable, Sequence
 import re
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING
 
 from homeassistant.const import CONF_PLATFORM
 
@@ -11,7 +11,9 @@ if TYPE_CHECKING:
     from .typing import ConfigType
 
 
-def config_per_platform(config: ConfigType, domain: str) -> Iterable[tuple[Any, Any]]:
+def config_per_platform(
+    config: ConfigType, domain: str
+) -> Iterable[tuple[str | None, ConfigType]]:
     """Break a component config into different platforms.
 
     For example, will find 'switch', 'switch 2', 'switch 3', .. etc
@@ -24,6 +26,8 @@ def config_per_platform(config: ConfigType, domain: str) -> Iterable[tuple[Any,
         if not isinstance(platform_config, list):
             platform_config = [platform_config]
 
+        item: ConfigType
+        platform: str | None
         for item in platform_config:
             try:
                 platform = item.get(CONF_PLATFORM)

homeassistant/helpers/entity_component.py

@@ -121,7 +121,8 @@ class EntityComponent:
 
         # Look in config for Domain, Domain 2, Domain 3 etc and load them
         for p_type, p_config in config_per_platform(config, self.domain):
-            self.hass.async_create_task(self.async_setup_platform(p_type, p_config))
+            if p_type is not None:
+                self.hass.async_create_task(self.async_setup_platform(p_type, p_config))
 
         # Generic discovery listener for loading platform dynamically
         # Refer to: homeassistant.helpers.discovery.async_load_platform()