Requests with scope type "websocket" raise a KeyError because there are no method for this kind of asgi request

[hartym]

The asgi scope definition for "websocket" requests does not contain a "method" entry (cf https://asgi.readthedocs.io/en/latest/specs/www.html#websocket-connection-scope). The BaseMiddleware from asgi-tools calls __process__ if scope in ("http", "websocket") (default, overridable at class level).

Thus this causes an exception for all websocket requests:

asgi-prometheus/asgi_prometheus/__init__.py

Line 70 in 630e0f7

path, method = scope["path"], scope["method"]

I'm not sure on how this should behave for websocket requests, I fix it for now be removing the "websocket" scope from the middleware scopes but this is a local workaround.

asgi_app = PrometheusMiddleware(asgi_app, metrics_url=_metrics_url, group_paths=["/"])
asgi_app.scopes = ("http",)