Correctly set required and nullable json schema values

pydantic_partial/_compat.py

@@ -14,7 +14,7 @@
 if PYDANTIC_V1:  # pragma: no cover
     from pydantic.fields import ModelField  # type: ignore
 
-    NULLABLE_KWARGS = {"nullable": True}
+    NULLABLE_KWARGS = {"nullable": True, "required": False}
 
     class PydanticCompat:  # type: ignore
         model_class: type[pydantic.BaseModel]
@@ -46,7 +46,7 @@ def copy_model_field_info(self, model_field: ModelField, **kwargs: Any) -> Field
             return copy_field_info(model_field.field_info, **kwargs)
 
 elif PYDANTIC_V2:  # pragma: no cover
-    NULLABLE_KWARGS = {"json_schema_extra": {"nullable": True}}
+    NULLABLE_KWARGS = {"json_schema_extra": {"nullable": True, "required": False}}
 
     class PydanticCompat:  # type: ignore
         model_class: type[pydantic.BaseModel]
@@ -65,7 +65,11 @@ def get_model_field_info_annotation(self, field_info: FieldInfo) -> Optional[typ
             return field_info.annotation
 
         def is_model_field_info_required(self, field_info: FieldInfo) -> bool:
-            return field_info.is_required()  # type: ignore
+            json_required = (
+                field_info.json_schema_extra is not None
+                and field_info.json_schema_extra.get("required", False)
+            )
+            return field_info.is_required() or json_required   # type: ignore
 
         def copy_model_field_info(self, field_info: FieldInfo, **kwargs: Any) -> FieldInfo:
             return copy_field_info(field_info, **kwargs)

pydantic_partial/partial.py

@@ -110,7 +110,7 @@ def _partial_annotation_arg(field_name_: str, field_annotation: type) -> type:
                         field_info,
                         default=None,  # Set default to None
                         default_factory=None,  # Remove default_factory if set
-                        **NULLABLE_KWARGS,  # For API usage: set field as nullable
+                        **NULLABLE_KWARGS,  # For API usage: set field as nullable and not required
                     ),
                 )
         elif recursive or sub_fields_requested:

tests/test_partial_without_mixin.py

@@ -12,7 +12,11 @@ def _field_is_required(model: Union[type[pydantic.BaseModel], pydantic.BaseModel
 elif PYDANTIC_V2:
     def _field_is_required(model: Union[type[pydantic.BaseModel], pydantic.BaseModel], field_name: str) -> bool:
         """Check if a field is required on a pydantic V2 model."""
-        return model.model_fields[field_name].is_required()
+        json_required = (
+            model.model_fields[field_name].json_schema_extra is not None
+            and model.model_fields[field_name].json_schema_extra.get("required", False)
+        )
+        return model.model_fields[field_name].is_required() or json_required
 else:
     raise DeprecationWarning("Pydantic has to be in version 1 or 2.")
 
@@ -21,6 +25,7 @@ class Something(pydantic.BaseModel):
     name: str
     age: int
     already_optional: None = None
+    already_required: int = pydantic.Field(default=1, json_schema_extra={"required": True})
 
 
 class SomethingWithMixin(PartialModelMixin, pydantic.BaseModel):
@@ -61,3 +66,9 @@ def test_partial_model_will_be_the_same_on_mixin():
     SomethingWithMixinPartial2 = SomethingWithMixin.model_as_partial()
 
     assert SomethingWithMixinPartial1 is SomethingWithMixinPartial2
+
+def test_partial_model_will_override_json_required():
+    SomethingPartial = create_partial_model(Something)
+    assert _field_is_required(SomethingPartial, "already_required") is False
+    SomethingPartial.model_json_schema()["properties"]["already_required"]["nullable"] is True
+    SomethingPartial.model_json_schema()["properties"]["already_required"]["required"] is False