[BUG] openapi.json fails to be generated for nested models

Describe the bug Fails to autogenerate docs.

To Reproduce

1. Create a response model with other nested models and try to generate openapi.json or open autogenerated docs.
2. Application throws an error

Expected behavior Generate openapi.json and open autogenerated docs without problems.

Environment:

• OS: macOS
• FastAPI Version: 0.30.0
• Python version: 3.7.3

Additional context

My models look like this:

class PaginatedItems(Generic[Item], BaseModel, abc.ABC):
    items: List[Any]
    has_after: bool = False
    has_before: bool = False

class OrderUser(BaseModel):
    name: Optional[str] = None
    email: EmailStr


class Order(BaseModel):
    order_id: UUID
    amount: Decimal
    currency: str

    # Users part
    merchants: List[OrderUser]
    handlers: List[OrderUser]

class PaginatedOrders(PaginatedItems[Order]):
    items: List[Order] = list()

My route definition looks like that:

@router.get(orders_uri,
            response_model=PaginatedOrders
async def list():
	...

This results in the following exception when trying to open autogenerated docs:

pydantic.error_wrappers.ValidationError: 4 validation errors
schemas -> OrderUser
  value is not a valid dict (type=type_error.dict)
schemas -> OrderUser
  value is not a valid dict (type=type_error.dict)
components -> schemas
  value is not none (type=type_error.none.allowed)
components
  value is not none (type=type_error.none.allowed)

When I comment out the response_model=PaginatedOrders part from route definition everything works, but docs obviously miss response type.

[euri10]

oups sorry I think your mistake is putting response_model=SimilarProducts, in the wrong spot, it’s in the @router part

[LKay]

I can confirm it now works fine! Thanks for fixing it so quickly!