Question 1570

AB Or BC

Figma's multiplayer server is authoritative and stores, per object and per property, the last value any client sent. There is no operational transform and no true CRDT: conflicts on one property resolve by whichever change the server processed last. The server rejects a parent change that would create a cycle in the object tree.

Two clients start from a document where text object T holds "A", and objects A and B are both children of the root. Both clients edit while offline from each other for a few milliseconds. The server processes their messages in the order shown.

Client 1 and client 2 changes as the server receives them client 1 server client 2 T.text = "AB" A.parent = B T.text = "BC" B.parent = A 1st 2nd 3rd 4th

What does the document contain once everything settles?

A

T.text is "AB"; both parent changes are rejected, so A and B both stay under the root.

B

T.text is "AB"; B is a child of A and A stays under the root.

C

T.text is "ABC"; B is a child of A and A stays under the root.

D

T.text is "BC"; A is a child of B and B stays under the root.