Try to fix coverage/types

Author: csm10495

frozenlist/__init__.py

@@ -106,7 +106,7 @@ def __reduce__(self):
         )
 
 
-def _reconstruct_pyfrozenlist(items, frozen):
+def _reconstruct_pyfrozenlist(items: list[Any], frozen: bool) -> "PyFrozenList":
     """Helper function to reconstruct the pure Python FrozenList during unpickling.
     This function is needed since otherwise the class renaming confuses pickle."""
     fl = PyFrozenList(items)

tests/test_frozenlist.py

@@ -274,6 +274,20 @@ def test_deepcopy_frozen(self) -> None:
         with pytest.raises(RuntimeError):
             copied.append(4)
 
+    def test_deepcopy_frozen_circular(self) -> None:
+        orig = self.FrozenList([1, 2])
+        orig.append(orig)  # Create circular reference
+        orig.freeze()
+        copied = deepcopy(orig)
+        assert copied[0] == 1
+        assert copied[1] == 2
+        assert len(copied[2]) == 3
+        assert copied[2][0] == 1
+        assert copied[2][1] == 2
+        assert len(copied[2][2]) == 3
+        # ... and so on. Testing equality when a structure includes itself is tough.
+        assert orig.frozen
+
     def test_deepcopy_nested(self) -> None:
         inner = self.FrozenList([1, 2])
         orig = self.FrozenList([inner, 3])