Passing a response with a list as a return to the fastapi the fastapi returns a strange json {"91":93} with 200 status

Description

By passing a response that return a empty list the fastapi returns this istrange json ‘{“91”:93}’. the situation can be reproduced by using the following code with fastapi

How to reproduce the problem

https://github.com/LeonardoLeano333/fastapi_example/blob/18925e2e7684d6a399fc6f59d6dabf77d35f2983/app/main.py my code: <main.py>

import requests
from app.src.sth_func import asd
from fastapi import FastAPI

app = FastAPI()

@app.post("/")
async def root():
    return []

@app.get("/up")
async def root_b():
    response = requests.post("http://localhost:8000/")
    
    return response

running two servers:

for the python request: uvicorn app.main:app --port 8081

for the inner response in the endpoint: uvicorn app.main:app --port 8000

the request:

>>> import requests
>>> asd = requests.get("http://localhost:8081/up/")
>>> asd
<Response [200]>
>>> asd.text
'{"91":93}'

Questions

I guess in this situation it should return a 500 or something like this but not a json that do not means much.

My question is why this is like this? Or what it should be if this answer fron the fast api is not correct?

[ComicShrimp]

I think that this problem is not related to the framework, is more related to programming itself. If the pieces work together, it works. In this case is more like a semantic error, where all the pieces work together, but don’t produce the result you want, and not a syntax error where the pieces don’t work together and it should return an error. This is my thought about this error.

Another thing that a founded in the example code, the functions have the same name, this could be causing the problems. You can try something like this:

import requests
from app.src.sth_func import asd
from fastapi import FastAPI

app = FastAPI()

@app.post("/")
async def root():
    return []

@app.get("/up")
async def root_2():
    response = requests.post("http://localhost:8000/")
    
    return response.json()

[github-actions[bot]]

Assuming the original need was handled, this will be automatically closed now. But feel free to add more comments or create new issues or PRs.