rstudio/plumber

POST bodies that can't be parsed should return HTTP 415 Unsupported Media Type

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#767 opened on Feb 8, 2021

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 (5 comments) (2 reactions) (0 assignees)R (1,437 stars) (257 forks)batch import
effort: lowhelp wantedtheme: postBody

Description

At present, if you decorate a POST endpoint with a parser (e.g. @parser json), and the client does not send you JSON data, you'll just see a message in the console and the endpoint handler will run anyway (even though, presumably, it will fail).

I don't think this is a particularly good way to surface errors to either the client or the operator -- even with the server logs, one can't use a generic message to track down which request had the problem.

Since this is a client error, the client should get a HTTP 4xx response. It turns out there is an existing HTTP status code for exactly this situation: 415 Unsupported Media Type. I'd like to see this returned instead. And, as with #757, I'd ideally like the response body/headers to be controllable.

Contributor guide

Tech stack
r
Domain
api
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
R programming basicsPlumber package basicsHTTP status codes
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Examine the parser functionality in R/parse body.R, specifically how errors are currently logged. The fix involves returning a 415 HTTP response when parsing fails. Consider how to make the response body and headers configurable, as hinted in the issue. There is no linked PR, but the discussion in comments may provide additional guidance.