In the frontend, we poll the status of an async job by repeatedly calling endpoints like /api/v1.0/corpus/155/query/:id/poll to show the progress bar for a particular task.

While working on haskell-gargantext#258 (closed) I have noticed that when the backend completes a job (i.e. the relevant async job is removed from the queue) the frontend emits this error:

This probably happens because now the communication socket has been closed on the server side, but the frontend should catch this scenario and ignore the error (or log it to the console as a warning) rather than spitting it in users' face.