✨ Add support for dependencies in WebSocket routes

[paulo-raca]

I've been using dependencies to handle authentication.
But imagine my surprise when I realized my websocket endpoint wasn't authenticated at all?

This commit cherry-picks the dependencies chunks from APIRoute into APIWebSocketRoute

I also made a few minor style nit-picks.

Here is a much-simplified code that demonstrates the issue:

import uvicorn
from fastapi import Depends, FastAPI, HTTPException,  WebSocket
from starlette.requests import Request, HTTPConnection
from starlette.websockets import WebSocket
from starlette.responses import PlainTextResponse, Response

def check_permission():
    print("check_permission")
    raise HTTPException(status_code=401, detail="Unauthorized")

app = FastAPI(dependencies=[Depends(check_permission)])

@app.get("/get")
def get_endpoint() -> Response:
    return PlainTextResponse("GET")

@app.websocket("/ws")
async def websocket_endpoint(ws: WebSocket):
    await ws.accept()
    await ws.send_text("Hello")

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)

As expected, accessing "/get" results in 401 error:

$ curl "http://localhost:8000/get"
{"detail":"Unauthorized"}

However the websocket endpoint remains accessible:

$ python -m websockets "ws://localhost:8000/ws"
Connected to ws://localhost:8000/ws.
< Hello
Connection closed: 1000 (OK).

After applying the patch, the dependencies execute successfully:

$ python -m websockets "ws://localhost:8000/ws"
Failed to connect to ws://localhost:8000/ws: server rejected WebSocket connection: HTTP 500.

Interestingly the websocket connection fails with code 500 instead of 401. I have addressed it into a separate PR to starlette

[paulo-raca]

Hello!

Is there anything missing on this PR?

[paulo-raca]

Thank you for the reviews, @BilalAlpaslan @cikay.

I just fixed the merge conflicts, it should be ready for merging

[paulo-raca]

@tiangolo, sorry to call you directly, but can I get your eyes on this?

This is a straightforward issue, but it has been bugging me a lot in the last month 😅

Thank you 🙏

[paulo-raca]

Anything missing from this change? How can I get it merged?

[github-actions]

📝 Docs preview for commit 6453788 at: https://62a95f500fa552369a8a9c11--fastapi.netlify.app

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (cf73051) 100.00% compared to head (ccc1987) 100.00%.

❗ Current head ccc1987 differs from pull request most recent head 931b492. Consider uploading reports for the commit 931b492 to get more accurate results

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #4534   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          540       541    +1     
  Lines        13969     14001   +32     
=========================================
+ Hits         13969     14001   +32     

Impacted Files	Coverage Δ
fastapi/applications.py	100.00% <100.00%> (ø)
fastapi/routing.py	100.00% <100.00%> (ø)
tests/test_ws_dependencies.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[github-actions]

📝 Docs preview for commit 73249da at: https://62a96d422ba68a456ea1be02--fastapi.netlify.app

[paulo-raca]

Merged master branch again 👍

@tiangolo, @Kludex, can I get eyes on this one?

Thanks!

[github-actions]

📝 Docs preview for commit 3945a32 at: https://6337d198c51f172ca119d1f5--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit e4ddcb8 at: https://633b8d39f6ae0b0073aa6272--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit 5943bae at: https://634eff6b41393725675bf3ea--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit ccc1987 at: https://6355f671a4e4cf7923aace28--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit f2541d2 at: https://639ce37dca15d5006470360d--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit 275208e at: https://63dfcc686a21a87de30b11e3--fastapi.netlify.app

[paulo-raca]

ping?

[lclbm]

Is there any progress about this issue?
have the same problem

[tiangolo]

📝 Docs preview for commit a463414 at: https://64861d40ff845b421d97876c--fastapi.netlify.app

[tiangolo]

Great, thank you @paulo-raca! 🚀 🙇

This will be available in the next version, FastAPI 0.97.0, released in the next hours (or tomorrow). 🎉

[paulo-raca]

Neat, thank you

[bastianh]

For me this was a breaking change because some dependencies I have on the router itself had Request as a dependency which is not available on the websocket endpoint... and those were suddenly executed for the websocket endpoint as well.

[gjanezic]

I have the same problem as @bastianh. How can we resolve this? Maybe related to #8503?

[tiangolo]

@bastianh and/or @gjanezic, please create a new discussion with a simple example I can copy paste and replicate your issue: https://github.com/tiangolo/fastapi/discussions/categories/questions 🙏