[whawk46]

Summary

• Detach __rune_parent on copy while preserving in-subtree parent links (Fixes model_copy(deep=True) follows __rune_parent links, producing an attached copy instead of a detached subtree. #49):
  • Override __copy__ and __deepcopy__ on BaseDataClass, basic-type metadata wrappers (BasicTypeMetaDataMixin / _DateTimeCopyMixin / NumberWithMeta), and _EnumWrapper so model_copy(deep=True), _clone_for_write, copy.copy, and copy.deepcopy detach the copied root from uncopied ancestors without traversing __rune_parent up the ancestor chain, while re-parenting cloned descendants inside the copied subtree.
  • Guard self.__dict__.get(name) in BaseDataClass.__setattr__ so model_copy(deep=True, update=...) does not raise KeyError when copying __pydantic_private__.
• Resolve and serialize references in list-typed fields (Fixes Bug: resolve_references does not resolve references held in list fields #43, addresses Multiple rune_deserialize / rune_serialize failures block CDM TradeState roundtrip #42 Bug 1 & Bug 4):
  • Extend BaseDataClass.resolve_references, _bind_property_to, _serialize_refs, _init_rune_parent, and resolve_ref_key to resolve UnresolvedReference / Reference elements held inside sequence fields and serialize bound reference indices back as {@ref*: key} dicts.
  • Fall back to extracting allowed @ref* tags from field validator metadata when _KEY_REF_CONSTRAINTS is not explicitly defined on the model class.
  • Guard ComplexTypeMetaDataMixin.serialise, BasicTypeMetaDataMixin.serialise, and EnumWithMetaMixin.serialise for None, list, and reference values when serializers wrap list-cardinality or optional fields.

Testing

• Added regression tests in test/test_rune_parent.py, test/test_keys_and_references.py, and test/test_list_cardinality_with_meta.py.
• pytest --cov=rune.runtime (369 passed).

[plamen-neykov]

This PR has some substantial issues:

1. List mutations silently serialize the wrong references. Bindings are stored by index, independently of the mutable list. Replacing observations[0] with a new inline object still serializes the old {"@ref": "obs-1"}, discarding the replacement. reverse() and pop() also corrupt the mapping. Neither resolve_references() nor validation repairs it.

2. += and copy-on-write list updates discard existing bindings. Once resolved, list elements are target objects rather than Reference instances. Assignment therefore enters the branch that removes the reference metadata. Serialization emits repeated inline definitions; deserializing that output fails with duplicate keys.

3. Rejected list assignments leave partial updates. The setter removes existing bindings and installs the new list before checking every reference. Assigning [valid_ref, wrong_type_ref] raises, but leaves the first item bound and the invalid second reference installed. Validation should complete before committing the replacement.

4. Detached subtree copies lose key lookup. When a nested model’s key registry lives in an ancestor, the copied subtree loses access to it. Existing resolved aliases survive, but Reference(key, parent=clone) raises KeyError. Detached copies need a registry built from their copied subtree.

[whawk46]

Thanks for the thorough review @plamen-neykov. All four points are addressed in commit c69f193:

1. In-place list mutations & reconciliation: Added _ReferenceList in src/rune/runtime/metadata.py and _reconcile_list_refs() in src/rune/runtime/base_data_class.py so index assignments (observations[0] = ...), slices, reverse(), pop(), insert(), del, and sort() update reference bindings in lockstep, with reconciliation on resolve_references(), validate_model(), and serialization (test_list_in_place_mutations_keep_reference_bindings_in_sync).
2. += and copy-on-write list updates: Preserved existing reference bindings across __iadd__ (+=), list concatenation (+), plain-list copy-on-write reassignments, and _COWList / rune_unwrap() in src/rune/runtime/cow.py (test_list_iadd_concat_and_cow_preserve_reference_bindings).
3. Atomic list assignment validation: _assign_sequence_property() now validates all Reference elements via _validate_ref_for_property() before mutating the list or __rune_references (test_rejected_list_reference_assignment_is_atomic).
4. Detached subtree key registries: BaseDataClass.__deepcopy__, __copy__, and model_copy now rebuild RUNE_OBJ_MAPS from the copied subtree via _rebuild_subtree_object_maps() / _rebuild_shallow_object_maps() so Reference(key, parent=clone) and get_object_by_key() resolve against detached copies (test_detached_subtree_copies_rebuild_key_registry).