Add significant change support to select entity (#51978)

homeassistant/components/select/significant_change.py

@@ -0,0 +1,19 @@
+"""Helper to test significant Select state changes."""
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.core import HomeAssistant, callback
+
+
+@callback
+def async_check_significant_change(
+    hass: HomeAssistant,
+    old_state: str,
+    old_attrs: dict,
+    new_state: str,
+    new_attrs: dict,
+    **kwargs: Any,
+) -> bool:
+    """Test if state significantly changed."""
+    return old_state != new_state

tests/components/select/test_significant_change.py

@@ -0,0 +1,20 @@
+"""Test the select significant change platform."""
+from homeassistant.components.select.significant_change import (
+    async_check_significant_change,
+)
+from homeassistant.core import HomeAssistant
+
+
+async def test_significant_change(hass: HomeAssistant) -> None:
+    """Detect select significant change."""
+    attrs1 = {"options": ["option1", "option2"]}
+    attrs2 = {"options": ["option1", "option2", "option3"]}
+
+    assert not async_check_significant_change(
+        hass, "option1", attrs1, "option1", attrs1
+    )
+    assert not async_check_significant_change(
+        hass, "option1", attrs1, "option1", attrs2
+    )
+    assert async_check_significant_change(hass, "option1", attrs1, "option2", attrs1)
+    assert async_check_significant_change(hass, "option1", attrs1, "option2", attrs2)