Add (deep)copy support to read only dict (#118204)

homeassistant/util/read_only_dict.py

@@ -1,5 +1,6 @@
 """Read only dictionary."""
 
+from copy import deepcopy
 from typing import Any
 
 
@@ -18,3 +19,13 @@ class ReadOnlyDict[_KT, _VT](dict[_KT, _VT]):
     clear = _readonly
     update = _readonly
     setdefault = _readonly
+
+    def __copy__(self) -> dict[_KT, _VT]:
+        """Create a shallow copy."""
+        return ReadOnlyDict(self)
+
+    def __deepcopy__(self, memo: Any) -> dict[_KT, _VT]:
+        """Create a deep copy."""
+        return ReadOnlyDict(
+            {deepcopy(key, memo): deepcopy(value, memo) for key, value in self.items()}
+        )

tests/util/test_read_only_dict.py

@@ -1,5 +1,6 @@
 """Test read only dictionary."""
 
+import copy
 import json
 
 import pytest
@@ -35,3 +36,5 @@ def test_read_only_dict() -> None:
     assert isinstance(data, dict)
     assert dict(data) == {"hello": "world"}
     assert json.dumps(data) == json.dumps({"hello": "world"})
+
+    assert copy.deepcopy(data) == {"hello": "world"}