Fix compatibility with Pydantic 2.13

openff/interchange/_tests/unit_tests/test_pydantic.py

@@ -10,7 +10,7 @@ class Person(_BaseModel):
 
 
 class Roster(_BaseModel):
-    people: dict[str, Person] = Field(dict())
+    people: dict[str, Person] = Field(default_factory=dict)
 
     foo: _Quantity = Field()
 

openff/interchange/components/interchange.py

@@ -82,7 +82,7 @@ class Interchange(_BaseModel):
 
     """
 
-    collections: _AnnotatedCollections = Field(dict())
+    collections: _AnnotatedCollections = Field(default_factory=dict)
     topology: _AnnotatedTopology
     mdconfig: MDConfig | None = Field(None)
     box: _BoxQuantity | None = Field(None)  # Needs shape/OpenMM validation

openff/interchange/components/potentials.py

@@ -40,7 +40,7 @@
 class Potential(_BaseModel):
     """Base class for storing applied parameters."""
 
-    parameters: dict[str, _Quantity] = Field(dict())
+    parameters: dict[str, _Quantity] = Field(default_factory=dict)
     map_key: int | None = None
 
     def __hash__(self) -> int:
@@ -439,7 +439,20 @@ def validate_collections(
         raise ValueError(f"Validation mode {info.mode} not implemented.")
 
 
+def serialize_collections(v: Any, handler: Any, info: Any) -> dict:
+    """Serialize collections using each collection's actual type schema.
+
+    Without this, pydantic uses the declared Collection base class schema and
+    drops subclass-specific fields (e.g. scale_14, cutoff, periodic_potential).
+    """
+    if info.mode == "json":
+        return {name: json.loads(collection.model_dump_json()) for name, collection in v.items()}
+    else:
+        raise NotImplementedError(f"Serialization mode {info.mode} not implemented.")
+
+
 _AnnotatedCollections = Annotated[
     dict[str, Collection],
     WrapValidator(validate_collections),
+    WrapSerializer(serialize_collections),
 ]

openff/interchange/pydantic.py

@@ -14,7 +14,7 @@ class _BaseModel(BaseModel):
     )
 
     def model_dump(self, **kwargs) -> dict[str, Any]:
-        return super().model_dump(serialize_as_any=True, **kwargs)
+        return super().model_dump(**kwargs)
 
     def model_dump_json(self, **kwargs) -> str:
-        return super().model_dump_json(serialize_as_any=True, **kwargs)
+        return super().model_dump_json(**kwargs)