I think that undefined at the end is not related to my code - it's there before those console logs appear and they're appended to the start of this table. In a

I think that undefined at the end is not related to my code - it's there before those console logs appear and they're appended to the start of this table. In any case I get the same result locally: I suspected doc2.cards would have length: 2, but it's only 1. I couldn't explain why so I rolled my own conflict-resolution scheme that fit my particular use case. It's primitive and doesn't actually give any guarantees, but gets the job done.