BDMS 221 & 227: function to retrieve polymorphic table record

tests/__init__.py

@@ -109,4 +109,42 @@ def cleanup_patch_test(model: Base, payload: dict, original_data: Base) -> None:
         session.commit()
 
 
+def retrieve_latest_polymorphic_table_record(
+    target_record: Base,
+    polymorphic_relationship: str,
+    polymorphic_type: str,
+) -> Base:
+    """
+    Retrieve the latest record from a polymorphic table. This function assumes that the
+    parent class has the correct mixin to support retrieval via an attribute. This
+    requires end_date to be None
+
+    Parameters:
+    ----------
+    target_record : Base
+        The parent record from which to retrieve the polymorphic child record.
+    polymorphic_relationship : str
+        The name of the relationship attribute on the parent record that corresponds to the polymorphic table.
+    polymorphic_type : str
+        The specific type of the polymorphic record to retrieve (e.g., 'Use Status' or 'Monitoring Status' for StatusHistory).
+    latest : bool, optional
+        If True, retrieves the latest record based on start_date. Defaults to True.
+    """
+    if polymorphic_relationship == "permissions":
+        type_field = "permission_type"
+    elif polymorphic_relationship == "status_history":
+        type_field = "status_type"
+
+    polymorphic_records = getattr(target_record, polymorphic_relationship)
+    type_polymorphic_records = [
+        r
+        for r in polymorphic_records
+        if getattr(r, type_field) == polymorphic_type and r.end_date is None
+    ]
+    sorted_type_polymorphic_records = sorted(
+        type_polymorphic_records, key=lambda r: r.start_date, reverse=True
+    )
+    return sorted_type_polymorphic_records[0]
+
+
 # ============= EOF =============================================