Restore persisted timeline state when loading history

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "objectstate"
-version = "1.0.23"
+version = "1.1.0"
 description = "Generic lazy dataclass configuration framework with dual-axis inheritance and contextvars-based resolution"
 authors = [{name = "Tristan Simas", email = "tristan.simas@mail.mcgill.ca"}]
 license = {text = "MIT"}

src/objectstate/__init__.py

@@ -214,7 +214,7 @@
     'ObjectStateEditSession',
 ]
 
-__version__ = "1.0.23"
+__version__ = "1.1.0"
 __author__ = 'OpenHCS Team'
 __description__ = 'Generic configuration framework for lazy dataclass resolution'
 

src/objectstate/object_state_registry.py

@@ -2172,7 +2172,7 @@ def save_history_to_file(cls, filepath: str) -> None:
 
     @classmethod
     def load_history_from_file(cls, filepath: str) -> None:
-        """Load a trusted type-preserving ObjectState history document.
+        """Load and materialize a trusted ObjectState history document.
 
         Args:
             filepath: Path to the binary ObjectState history document.
@@ -2181,4 +2181,13 @@ def load_history_from_file(cls, filepath: str) -> None:
 
         with open(filepath, "rb") as history_file:
             cls.import_history_from_dict(dill.load(history_file))
+        restored_at_head = cls._current_head is None
+        snapshot_id = cls._current_snapshot_id()
+        if snapshot_id is not None:
+            if not cls.time_travel_to_snapshot(snapshot_id):
+                raise RuntimeError(
+                    "Loaded ObjectState history could not restore its current snapshot."
+                )
+            if restored_at_head:
+                cls._current_head = None
         logger.info(f"⏱️ Loaded {len(cls._snapshots)} snapshots from {filepath}")

tests/test_history_persistence.py

@@ -58,3 +58,29 @@ def test_history_file_round_trips_typed_values(tmp_path: Path) -> None:
     assert parameters["mode"] is HistoryMode.FAST
     assert parameters["transform"] is identity
     assert history_path.stat().st_size > 0
+
+
+def test_history_file_materializes_current_snapshot_into_registered_state(
+    tmp_path: Path,
+) -> None:
+    state = ObjectState(
+        HistoryConfig(
+            output_path=tmp_path / "before",
+            mode=HistoryMode.FAST,
+            transform=identity,
+        ),
+        scope_id="restored_history",
+    )
+    ObjectStateRegistry.register(state, _skip_snapshot=True)
+    ObjectStateRegistry.record_snapshot("baseline", scope_id=state.scope_id)
+    state.update_parameter("output_path", tmp_path / "persisted")
+    ObjectStateRegistry.record_snapshot("persisted edit", scope_id=state.scope_id)
+    history_path = tmp_path / "history.objectstate"
+    ObjectStateRegistry.save_history_to_file(str(history_path))
+
+    state.update_parameter("output_path", tmp_path / "after-save")
+    ObjectStateRegistry.load_history_from_file(str(history_path))
+
+    assert state.parameters["output_path"] == tmp_path / "persisted"
+    assert state.to_resolved_object().output_path == tmp_path / "persisted"
+    assert ObjectStateRegistry.get_current_snapshot_index() == -1