test: add regression test for additionalProperties nullable+allOf+ref

Author: hsunner

tests/conftest.py

@@ -449,6 +449,11 @@ def with_schema_additionalProperties_and_named_properties():
     yield _get_parsed_yaml("schema-additionalProperties-and-named-properties.yaml")
 
 
+@pytest.fixture
+def with_schema_additionalProperties_nullable_allof():
+    yield _get_parsed_yaml("schema-additionalProperties-nullable-allof.yaml")
+
+
 @pytest.fixture
 def with_schema_date_types():
     yield _get_parsed_yaml("schema-date-types.yaml")

tests/fixtures/schema-additionalProperties-nullable-allof.yaml

@@ -0,0 +1,38 @@
+openapi: "3.0.3"
+info:
+  version: 1.0.0
+  title: additionalProperties nullable allOf
+
+components:
+  schemas:
+    LinkOccasion:
+      type: object
+      properties:
+        unitTestId:
+          type: integer
+
+    RelationsModel:
+      type: object
+      properties:
+        unitPartNumber:
+          type: string
+        linkOccasions:
+          type: array
+          items:
+            $ref: "#/components/schemas/LinkOccasion"
+
+paths:
+  /relations:
+    get:
+      operationId: getRelations
+      responses:
+        "200":
+          description: ok
+          content:
+            application/json:
+              schema:
+                type: object
+                additionalProperties:
+                  nullable: true
+                  allOf:
+                    - $ref: "#/components/schemas/RelationsModel"

tests/schema_test.py

@@ -332,6 +332,31 @@ def test_schema_with_additionalProperties_and_named_properties(with_schema_addit
     assert b.aio3_additionalProperties["foo"] == "bar"
 
 
+def test_schema_additionalProperties_nullable_allof(with_schema_additionalProperties_nullable_allof):
+    """
+    Inline additionalProperties schema with nullable+allOf+$ref must produce a fully
+    resolved Pydantic model (regression test for _get_combined_attributes omitting
+    additionalProperties from schema traversal).
+    """
+    api = OpenAPI("/", with_schema_additionalProperties_nullable_allof)
+
+    schema = api.paths["/relations"].get.responses["200"].content["application/json"].schema_
+    value_type = schema.additionalProperties.get_type()
+
+    assert value_type.__pydantic_complete__ is True
+
+    # non-null value
+    obj = value_type.model_validate({"unitPartNumber": "ABC", "linkOccasions": [{"unitTestId": 1}]})
+    assert obj.unitPartNumber == "ABC"
+    assert obj.linkOccasions[0].unitTestId == 1
+
+    # map model accepts null values for the map entries
+    map_type = schema.get_type()
+    result = map_type.model_validate({"key1": {"unitPartNumber": "ABC", "linkOccasions": []}, "key2": None})
+    assert result.root["key2"] is None
+    assert result.root["key1"].unitPartNumber == "ABC"
+
+
 def test_schema_with_patternProperties(with_schema_patternProperties):
     api = OpenAPI("/", with_schema_patternProperties)
     A = api.components.schemas["A"].get_type()