Agree there is a problem with the request - so I get an error. My question is aimed at why getErrorJson() throws an exception, when getErrorData() shows a JSON response body?
Just guessing, but are you specifying a content type for either your request or response when you run the async HTTP method (assuming you aren't using the dedicated JSON method already)?
404 -- to be clear, at this point I'm expecting an error, and trying to understand the error parsing/handling. I can, of course, parse the JSON manually using JsonSlurper -- but I don't think I should have to...
Yep, I agree. Smells like a bug to me. It's valid JSON and an actual error status value (not like 2xx because of something quirky with the server response).