alt Hacker NewsThat depends on how Postel's law is interpreted.
What's reasonable is: "Set reserved fields to 0 when writing and ignore them when reading." (I heard that was the original example). Or "Ignore unknown JSON keys" as a modern equivalent.
What's harmful is: Accept an ill defined superset of the valid syntax and interpret it in undocumented ways.
Replies
treve • yesterday at 8:26 PM
Good modern protocols will explicitly define extension points, so 'ingoring unknown JSON keys' is in-spec rather than assumed that an implementer will do.
yxhuvud • yesterday at 8:49 PM
I disagree. I find accepting extra random bytes in places to be just as harmful. I prefer APIs that push back and tell me what I did wrong when I mess up.
Funny I never read the original example. And in my book, it is harmful, and even worse in JSON, since it's the best way to have a typo somewhere go unnoticed for a long time.