Breaking changes in Trello's Update Card API call?

[David Tavdi]

Recently, our integration with Trello started to remove cards' cover images each time we call PUT /card to update something on a card (usually due dates, description, or moving a card around)

After investigating the code, I found out that there's a "cover": {} field persisted in the call's body. Meaning there's an empty object for a cover. For many years, this empty object was ignored, but something changed, and now it is considered an erosion of the cover. 

Can someone confirm this? And is it a bug or a feature?

[Sunny Ape · Accepted solution]

Hello @David Tavdi 

When updating a card, setting the value of the cover object to nothing has always removed the cover. However, if your JSON was:

{
   "cover": {}
}

that is invalid JSON (as there's nothing declared inside the second set) so the parser has probably just been rejecting (ignoring) it all this time.

I assume the parser has been updated to interpret that JSON as:

{
   "cover": ""
}

which is valid JSON and sets the cover as empty (removes it), as expected

So in reality, it was your JSON that contained the bug and the interpreter is now just doing a more 'correct' interpretation of what your JSON was trying to say, and that change could be considered a feature.