From 4085c4f6d86fbbe47840341eb552d2e44018231e Mon Sep 17 00:00:00 2001
From: Erik Montnemery <erik@montnemery.com>
Date: Fri, 9 Jun 2023 10:56:04 +0200
Subject: [PATCH] Tweak typing of Entity.platform (#88321)

* Tweak typing of Entity.platform

* Fix mypy errors

* Fix update test

* Improve comments
---
 homeassistant/components/rflink/__init__.py |  1 -
 homeassistant/components/update/__init__.py |  3 ---
 homeassistant/helpers/entity.py             | 10 ++++++----
 tests/components/update/test_init.py        | 13 +++++--------
 4 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/homeassistant/components/rflink/__init__.py b/homeassistant/components/rflink/__init__.py
index b563275297f..8df2d7ec343 100644
--- a/homeassistant/components/rflink/__init__.py
+++ b/homeassistant/components/rflink/__init__.py
@@ -323,7 +323,6 @@ class RflinkDevice(Entity):
     Contains the common logic for Rflink entities.
     """
 
-    platform = None
     _state: bool | None = None
     _available = True
     _attr_should_poll = False
diff --git a/homeassistant/components/update/__init__.py b/homeassistant/components/update/__init__.py
index 3c8a30d5b4f..e0244034865 100644
--- a/homeassistant/components/update/__init__.py
+++ b/homeassistant/components/update/__init__.py
@@ -236,9 +236,6 @@ class UpdateEntity(RestoreEntity):
         Update entities return the brand icon based on the integration
         domain by default.
         """
-        if self.platform is None:
-            return None
-
         return (
             f"https://brands.home-assistant.io/_/{self.platform.platform_name}/icon.png"
         )
diff --git a/homeassistant/helpers/entity.py b/homeassistant/helpers/entity.py
index ef526f956cd..cdb20833a3d 100644
--- a/homeassistant/helpers/entity.py
+++ b/homeassistant/helpers/entity.py
@@ -235,13 +235,15 @@ class Entity(ABC):
     # this class. These may be used to customize the behavior of the entity.
     entity_id: str = None  # type: ignore[assignment]
 
-    # Owning hass instance. Will be set by EntityPlatform
+    # Owning hass instance. Set by EntityPlatform by calling add_to_platform_start
     # While not purely typed, it makes typehinting more useful for us
     # and removes the need for constant None checks or asserts.
     hass: HomeAssistant = None  # type: ignore[assignment]
 
-    # Owning platform instance. Will be set by EntityPlatform
-    platform: EntityPlatform | None = None
+    # Owning platform instance. Set by EntityPlatform by calling add_to_platform_start
+    # While not purely typed, it makes typehinting more useful for us
+    # and removes the need for constant None checks or asserts.
+    platform: EntityPlatform = None  # type: ignore[assignment]
 
     # Entity description instance for this Entity
     entity_description: EntityDescription
@@ -840,7 +842,7 @@ class Entity(ABC):
         self._call_on_remove_callbacks()
 
         self.hass = None  # type: ignore[assignment]
-        self.platform = None
+        self.platform = None  # type: ignore[assignment]
         self.parallel_updates = None
 
     async def add_to_platform_finish(self) -> None:
diff --git a/tests/components/update/test_init.py b/tests/components/update/test_init.py
index d0546b6a2ef..a7780f54f70 100644
--- a/tests/components/update/test_init.py
+++ b/tests/components/update/test_init.py
@@ -49,6 +49,7 @@ async def test_update(hass: HomeAssistant) -> None:
     """Test getting data from the mocked update entity."""
     update = MockUpdateEntity()
     update.hass = hass
+    update.platform = MockEntityPlatform(hass)
 
     update._attr_installed_version = "1.0.0"
     update._attr_latest_version = "1.0.1"
@@ -57,7 +58,10 @@ async def test_update(hass: HomeAssistant) -> None:
     update._attr_title = "Title"
 
     assert update.entity_category is EntityCategory.DIAGNOSTIC
-    assert update.entity_picture is None
+    assert (
+        update.entity_picture
+        == "https://brands.home-assistant.io/_/test_platform/icon.png"
+    )
     assert update.installed_version == "1.0.0"
     assert update.latest_version == "1.0.1"
     assert update.release_summary == "Summary"
@@ -76,13 +80,6 @@ async def test_update(hass: HomeAssistant) -> None:
         ATTR_TITLE: "Title",
     }
 
-    # Test with platform
-    update.platform = MockEntityPlatform(hass)
-    assert (
-        update.entity_picture
-        == "https://brands.home-assistant.io/_/test_platform/icon.png"
-    )
-
     # Test no update available
     update._attr_installed_version = "1.0.0"
     update._attr_latest_version = "1.0.0"