Ensure history states can be copied (#37081)

The filter integration makes a copy of a
state object obtained from history.

homeassistant/components/history/__init__.py

@@ -616,7 +616,7 @@ class LazyState(State):
         self._last_updated = None
         self._context = None
 
-    @property
+    @property  # type: ignore
     def attributes(self):
         """State attributes."""
         if not self._attributes:
@@ -628,13 +628,23 @@ class LazyState(State):
                 self._attributes = {}
         return self._attributes
 
-    @property
+    @attributes.setter
+    def attributes(self, value):
+        """Set attributes."""
+        self._attributes = value
+
+    @property  # type: ignore
     def context(self):
         """State context."""
         if not self._context:
             self._context = Context(id=None)
         return self._context
 
+    @context.setter
+    def context(self, value):
+        """Set context."""
+        self._context = value
+
     @property  # type: ignore
     def last_changed(self):
         """Last changed datetime."""

tests/components/history/test_init.py

@@ -1,5 +1,6 @@
 """The tests the History component."""
 # pylint: disable=protected-access,invalid-name
+from copy import copy
 from datetime import timedelta
 import json
 import unittest
@@ -188,6 +189,39 @@ class TestComponentHistory(unittest.TestCase):
 
         assert states == hist[entity_id]
 
+    def test_ensure_state_can_be_copied(self):
+        """Ensure a state can pass though copy().
+
+        The filter integration uses copy() on states
+        from history.
+        """
+        self.init_recorder()
+        entity_id = "sensor.test"
+
+        def set_state(state):
+            """Set the state."""
+            self.hass.states.set(entity_id, state)
+            wait_recording_done(self.hass)
+            return self.hass.states.get(entity_id)
+
+        start = dt_util.utcnow() - timedelta(minutes=2)
+        point = start + timedelta(minutes=1)
+
+        with patch(
+            "homeassistant.components.recorder.dt_util.utcnow", return_value=start
+        ):
+            set_state("1")
+
+        with patch(
+            "homeassistant.components.recorder.dt_util.utcnow", return_value=point
+        ):
+            set_state("2")
+
+        hist = history.get_last_state_changes(self.hass, 2, entity_id)
+
+        assert copy(hist[entity_id][0]) == hist[entity_id][0]
+        assert copy(hist[entity_id][1]) == hist[entity_id][1]
+
     def test_get_significant_states(self):
         """Test that only significant states are returned.