Access logs not properly displaying body size

[ahopkins]

In certain circumstances, the access logger is displaying the wrong body size.

@app.post("/")
async def post(request):
    print(request.json)

$ curl localhost:9999 -d '{"foo": "bar"}

{'foo': 'bar'}
[2021-04-18 01:43:33 +0300] - (sanic.access)[INFO][127.0.0.1:52172]: POST http://localhost:9999/  200 -1

In this example, it is being reported as -1