[BUG] null returned for 204

Hi,

we’re running Python 3.7.3 with FastAPI 0.27.2 and have the following API definition (simplified):

app.post("/url", status_code = HTTP_204_OK)
async def set_data(data: Data) -> None: 
   await db.set_data(data)

We return a 204 and return nothing in the body but we see that null is returned with a content length of 4. The client expect content-length = 0 for a 204 response. Can this please be fixed?

Thanks, Daniel

[dmontagu]

To add to @euri10 's point, you can similarly fix this via:

from starlette.responses import Response

@app.post("/url", status_code = HTTP_204_OK, response_class=Response)
async def set_data(data: Data) -> None: 
   await db.set_data(data)

[euri10]

Still baffled about the null return, but workaround works so I’ll close the ticket.

Thanks

I agree, maybe worth a ping upstream as the current API let you return a 204 with content, which shouldn’t be possible