[Bug] Dependency injection not working for websocket handlers

[xmcp]

Describe the bug

Sanic-Ext fails to inject dependencies to @app.websocket() handlers.

Screenshots

To Reproduce

Try this code:

from sanic import Sanic

app = Sanic('test')

class Foo:
    pass
    
app.ext.add_dependency(Foo, lambda req: None)

@app.websocket('/foo')
async def handler(req, ws, foo: Foo):
    pass
    
app.run(port=4321, debug=True)

Visit http://127.0.0.1:4321/, then execute new WebSocket('ws://127.0.0.1:4321/foo') in browser console.

This error will be thrown:

Traceback (most recent call last):
  File "handle_request", line 83, in handle_request
    )
  File "C:\Users\xmcp\AppData\Roaming\Python\Python38\site-packages\sanic\app.py", line 1002, in _websocket_handler
    fut = ensure_future(handler(request, ws, *args, **kwargs))
TypeError: handler() missing 1 required positional argument: 'foo'

Expected behavior

It should not throw an error.

Environment (please complete the following information):

• OS: Windows 10 (19044.1466)
• Browser: not related
• Version: sanic 21.12.1, sanic-ext 22.1.2

Additional context

Sanic wraps a functools.partial to the websocket handler, effectively erasing the type signature of the handler function. Therefore sanic_ext.extensions.injection.injector (screenshot below) cannot get its type hint:

[ahopkins]

Thanks @xmcp for bringing this up. We will have this fixed in the upcoming release next week.