how to make JSON decoding throw an error for superfluous elements in JSON input

Hi! How can I make the Circe JSON decoding stricter such that whenever it encounters an element (in the JSON input string) that is not in the target class X (decode[X](string)) it throws an error. Currently, with the default settings (circe 0.9.1), superfluous elements are silently ignored. For me (in my application) superfluous elements are an input error, so I need the error to be thrown by circe. Thanks!

[daddykotex]

I ask the following to learn more, not claim a solution by any means.

yeah, I answered just to share where I’ve seen this 😃

Why can’t you, per your example, make elements a required field then?

Well, that’s another perfectly valid solution in my opinion. One reason you might not be able to do that is that you have to support older clients, and elements is something new in the payload.

[hansschl]

@travisbrown Sure: I’ve tried the #708 example (with circe 0.9.1). In that example, decoding should work for good and shouldBeGood, although it does only for good.