JSONPB json parsing not rejecting unknown fields by default as it should according to spec

[arobertn]

Proto3 JSON parsers are supposed to reject unknown fields unless explicitly requested to ignore them. But I cannot find an option for this in JSONPB .eitherDecode; it operates in ignore mode. Am I missing something?

[Gabriella439]

So I looked into this and it appears that this would require a breaking change to the API. Specifically parseJSONPB would need to take an additional Options argument (similar to toJSONPB)