Add NX584 alarm binary_sensor zone_number attribute (#36552)

homeassistant/components/nx584/binary_sensor.py

@@ -101,6 +101,11 @@ class NX584ZoneSensor(BinarySensorEntity):
         # True means "faulted" or "open" or "abnormal state"
         return self._zone["state"]
 
+    @property
+    def device_state_attributes(self):
+        """Return the state attributes."""
+        return {"zone_number": self._zone["number"]}
+
 
 class NX584Watcher(threading.Thread):
     """Event listener thread to process NX584 events."""

tests/components/nx584/test_binary_sensor.py

@@ -135,6 +135,7 @@ class TestNX584ZoneSensor(unittest.TestCase):
         assert "foo" == sensor.name
         assert not sensor.should_poll
         assert sensor.is_on
+        assert sensor.device_state_attributes["zone_number"] == 1
 
         zone["state"] = False
         assert not sensor.is_on