with 'uvicorn==0.21.0' modifications made to the 'request.state' persist between requests

[yromanyshyn]

support of the lifespan state and the notion of the app_state was added to the latest release of the uvicorn, as result, now changes made to the request.state persist between requests (actually in a very weird way/), IMO, it is confusing and unexpected behavior, you do not expect that changes made to the request state will outlive the request/

Code snippet:

from starlette.applications import Starlette
from starlette.responses import PlainTextResponse
from starlette.routing import Route

def handler(request):
    if not hasattr(request.state, "foo"):
        request.state.foo = 10
    else:
        request.state.foo += 1
    return PlainTextResponse(f"Foo: {request.state.foo}")

app = Starlette(debug=True, routes=[Route('/', handler),])

Demonstration:
(please, look the video to the end)

simplescreenrecorder-.3.mp4

Installed packages and python version:

>> pip freeze
anyio==3.6.2
click==8.1.3
h11==0.14.0
idna==3.4
sniffio==1.3.0
starlette==0.26.1
typing-extensions==4.5.0
uvicorn==0.21.0

>> python --version
Python 3.8.10

[Kludex]

It's a bug on uvicorn, not on Starlette.

It looks like the state is persisting per connection, not per request.

cc @adriangb (I can fix it later, just letting you know)