Using the ASGI app as a Starlette route throws typing errors

[parafoxia]

Describe the Bug

The following code is more or less a copy of what appears in the docs:

from starlette.applications import Starlette
from strawberry.asgi import GraphQL

from .schema import schema

app = Starlette()
graphql = GraphQL[None, None](schema)
app.add_route("/graphql", route=graphql)

However, it raises the following typing error:

app.py:8: error: Argument 2 to "add_route" of "Starlette" has incompatible type "GraphQL[Any, Any]"; expected "Callable[[Request], Awaitable[Response] | Response]"  [arg-type]
app.py:8: note: "GraphQL[Any, Any].__call__" has type "Callable[[Arg(MutableMapping[str, Any], 'scope'), Arg(Callable[[], Awaitable[MutableMapping[str, Any]]], 'receive'), Arg(Callable[[MutableMapping[str, Any]], Awaitable[None]], 'send')], Coroutine[Any, Any, None]]"

While the code does actually run and appears to function correctly, Mypy is flagging incompatible signatures.

The signature for the route parameter for the add_route method:

(Request) -> (Awaitable[Response] | Response)

The signature of the GraphQL.__call__ method:

(Scope, Receive, Send) -> (None)

The latter signature is the same as the signature for Starlette middleware. I'm presuming Mypy is getting confused, or something isn't properly deliniated to Mypy and it's assuming something it shouldn't be, as the code does work.

It's also worth noting that the documentation should be updated to use full type annotations.

System Information

• Operating system: MacOS
• Strawberry version (if applicable): 0.235.0

Additional Context

Starlette version 0.37.2.

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