Fix allOf partial property overrides to inherit parent types instead of Any (#2654)

* Fix inheritance of parent field types for allOf partial overrides

* Fix inherited field type resolution for allOf with partial overrides

Author: koxudaxi

src/datamodel_code_generator/parser/jsonschema.py

@@ -1519,6 +1519,24 @@ def _parse_object_common_part(  # noqa: PLR0912, PLR0913
                     class_name=name,
                 )
             )
+        if base_classes:
+            for field in fields:
+                current_type = field.data_type
+                field_name = field.original_name or field.name
+                if current_type and current_type.type == ANY and field_name:
+                    inherited_type = self._get_inherited_field_type(field_name, base_classes)
+                    if inherited_type is not None:
+                        if PYDANTIC_V2:
+                            new_type = inherited_type.model_copy(deep=True)
+                        else:
+                            new_type = inherited_type.copy(deep=True)
+                        new_type.is_optional = new_type.is_optional or current_type.is_optional
+                        new_type.is_dict = new_type.is_dict or current_type.is_dict
+                        new_type.is_list = new_type.is_list or current_type.is_list
+                        new_type.is_set = new_type.is_set or current_type.is_set
+                        if new_type.kwargs is None and current_type.kwargs is not None:  # pragma: no cover
+                            new_type.kwargs = current_type.kwargs
+                        field.data_type = new_type
         # ignore an undetected object
         if ignore_duplicate_model and not fields and len(base_classes) == 1:
             with self.model_resolver.current_base_path_context(self.model_resolver._base_path):  # noqa: SLF001

tests/data/expected/main/jsonschema/all_of_ref_with_property_override.py

@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Any, Optional
+from typing import Optional
 
 from pydantic import BaseModel, constr
 
@@ -15,6 +15,6 @@ class Thing(BaseModel):
 
 
 class Person(Thing):
-    type: Optional[Any] = 'playground:Person'
-    name: Optional[Any] = None
+    type: Optional[str] = 'playground:Person'
+    name: Optional[constr(min_length=1)] = None
     age: Optional[int] = None

tests/data/expected/main/openapi/allof_partial_override_inherited_types.py

@@ -0,0 +1,20 @@
+# generated by datamodel-codegen:
+#   filename:  allof_partial_override_inherited_types.yaml
+#   timestamp: 2019-07-26T00:00:00+00:00
+
+from __future__ import annotations
+
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+class Thing(BaseModel):
+    type: Optional[str] = None
+    name: Optional[str] = Field(None, description='First and Last name')
+
+
+class Person(Thing):
+    type: Optional[str] = 'playground:Person'
+    name: str = Field(..., description='First and Last name')
+    age: Optional[int] = None

tests/data/openapi/allof_partial_override_inherited_types.yaml

@@ -0,0 +1,24 @@
+openapi: "3.0.0"
+components:
+  schemas:
+    Thing:
+      type: object
+      properties:
+        type:
+          type: string
+        name:
+          type: string
+          description: First and Last name
+    Person:
+      allOf:
+        - $ref: "#/components/schemas/Thing"
+        - type: object
+          properties:
+            type:
+              default: playground:Person
+            name:
+              description: First and Last name
+            age:
+              type: integer
+          required:
+            - name

tests/main/openapi/test_main_openapi.py

@@ -1719,6 +1719,17 @@ def test_main_openapi_allof_with_required_inherited_comprehensive(output_file: P
     )
 
 
+def test_main_openapi_allof_partial_override_inherited_types(output_file: Path) -> None:
+    """Test OpenAPI allOf partial overrides inherit parent field types."""
+    run_main_and_assert(
+        input_path=OPEN_API_DATA_PATH / "allof_partial_override_inherited_types.yaml",
+        output_path=output_file,
+        input_file_type="openapi",
+        assert_func=assert_file_content,
+        expected_file="allof_partial_override_inherited_types.py",
+    )
+
+
 def test_main_openapi_allof_with_required_inherited_edge_cases(output_file: Path) -> None:
     """Test OpenAPI generation with allOf edge cases for branch coverage."""
     run_main_and_assert(