Add significant change support to binary_sensor (#45677)

* Add significant change support to binary_sensor

homeassistant/components/binary_sensor/significant_change.py

@@ -0,0 +1,20 @@
+"""Helper to test significant Binary Sensor state changes."""
+from typing import Any, Optional
+
+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,
+) -> Optional[bool]:
+    """Test if state significantly changed."""
+    if old_state != new_state:
+        return True
+
+    return False

homeassistant/components/binary_sensor/translations/en.json

@@ -159,8 +159,8 @@
             "on": "Plugged in"
         },
         "presence": {
-            "off": "Away",
-            "on": "Home"
+            "off": "[%key:common::state::not_home%]",
+            "on": "[%key:common::state::home%]"
         },
         "problem": {
             "off": "OK",

tests/components/binary_sensor/test_significant_change.py

@@ -0,0 +1,20 @@
+"""Test the Binary Sensor significant change platform."""
+from homeassistant.components.binary_sensor.significant_change import (
+    async_check_significant_change,
+)
+
+
+async def test_significant_change():
+    """Detect Binary Sensor significant changes."""
+    old_attrs = {"attr_1": "value_1"}
+    new_attrs = {"attr_1": "value_2"}
+
+    assert (
+        async_check_significant_change(None, "on", old_attrs, "on", old_attrs) is False
+    )
+    assert (
+        async_check_significant_change(None, "on", old_attrs, "on", new_attrs) is False
+    )
+    assert (
+        async_check_significant_change(None, "on", old_attrs, "off", old_attrs) is True
+    )