Question: Response headers needs to be set/assigned again

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Example

So, the following code is simple. Sets headers and done! BUT it’s not how it looks like.

from fastapi import FastAPI, Response
from fastapi.responses import RedirectResponse, FileResponse
from os.path import isfile

app = FastAPI()


@app.get("/")
def read_root(resp: Response):
    resp.headers['foo'] = 'bar'
    return RedirectResponse('https://printer.discord.com')

# OR the FileResponse
@app.get("/baz/{location:path}")
def read_baz(resp: Response):
    if isfile(location):
        return FileResponse(location)

Description

• Open the browser and call the endpoint /.
• It returns a 307 Temporary Redirect to bla bla… BUT WITHOUT THE HEADERS
• Well, the fix is simple. RedirectResponse(..., headers=resp.headers) BUT it actually took me a while to think of it and it would be awesome to see objects within fastapi.responses actually respect fastapi.Response.

Environment

• OS: macOS
• FastAPI Version: 0.65.0
• Python version: Python 3.9.5

[naryal2580]

Makes sense, another object is another object, and objects acting polymorphic could be a nightmare while debugging.

[FalseDev]

You’re mutating the headers in a different object and not returning that object. I’d (and probably most others) prefer this behavior over what you’re suggesting.