fix: handle discriminated model with root definition

aiohttp_pydantic/injectors.py

@@ -68,7 +68,10 @@ class BodyGetter(AbstractInjector):
 
     def __init__(self, args_spec: dict, default_values: dict):
         self.arg_name, self.model = next(iter(args_spec.items()))
-        self._expect_object = self.model.schema()["type"] == "object"
+        schema = self.model.schema()
+        if "type" not in schema:
+            schema["type"] = "object"
+        self._expect_object = schema["type"] == "object"
 
     async def inject(self, request: BaseRequest, args_view: list, kwargs_view: dict):
         try:

tests/test_oas/test_view.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from enum import Enum
-from typing import List, Optional, Union, Literal
+from typing import List, Optional, Union, Literal, Annotated
 from uuid import UUID
 
 import pytest
@@ -42,6 +42,20 @@ class Error(BaseModel):
     text: str
 
 
+class Cat(BaseModel):
+    pet_type: Literal['cat']
+    meows: int
+
+
+class Dog(BaseModel):
+    pet_type: Literal['dog']
+    barks: float
+
+
+class Animal(BaseModel):
+    __root__: Annotated[Union[Cat, Dog], Field(discriminator='pet_type')]
+
+
 class PetCollectionView(PydanticView):
     async def get(
             self, format: str, lang: Lang = Lang.EN, name: Optional[str] = None, *, promo: Optional[UUID] = None
@@ -91,6 +105,11 @@ class ViewResponseReturnASimpleType(PydanticView):
         return web.json_response()
 
 
+class DiscriminatedView(PydanticView):
+    async def post(self, /, request: Animal) -> r200[int]:
+        return web.json_response()
+
+
 async def ensure_content_durability(client):
     """
     Reload the page 2 times to ensure that content is always the same
@@ -115,6 +134,7 @@ async def generated_oas(aiohttp_client, event_loop) -> web.Application:
     app.router.add_view("/pets", PetCollectionView)
     app.router.add_view("/pets/{id}", PetItemView)
     app.router.add_view("/simple-type", ViewResponseReturnASimpleType)
+    app.router.add_view("/animals", DiscriminatedView)
     oas.setup(app)
 
     return await ensure_content_durability(await aiohttp_client(app))
@@ -122,12 +142,26 @@ async def generated_oas(aiohttp_client, event_loop) -> web.Application:
 
 async def test_generated_oas_should_have_components_schemas(generated_oas):
     assert generated_oas["components"]["schemas"] == {
+        'Cat': {'properties': {'meows': {'title': 'Meows', 'type': 'integer'},
+                               'pet_type': {'enum': ['cat'],
+                                            'title': 'Pet Type',
+                                            'type': 'string'}},
+                'required': ['pet_type', 'meows'],
+                'title': 'Cat',
+                'type': 'object'},
         "Color": {
             "description": "An enumeration.",
             "enum": ["red", "green", "pink"],
             "title": "Color",
             "type": "string",
         },
+        'Dog': {'properties': {'barks': {'title': 'Barks', 'type': 'number'},
+                               'pet_type': {'enum': ['dog'],
+                                            'title': 'Pet Type',
+                                            'type': 'string'}},
+                'required': ['pet_type', 'barks'],
+                'title': 'Dog',
+                'type': 'object'},
         'Error': {
             'properties': {
                 'code': {'title': 'Code', 'type': 'integer'},