Lattice

Try to break it.

Three copies of one board, joined by a simulated network. Click a wire to cut it. Make the network slow and lossy. Type into different copies while they can't see each other. When you reconnect, every copy lands on the same text and the same fingerprint.

Things to try

  1. Same spot, same time. Cut every wire, put the cursor at the end of the note in A and in C, and type different words. Reconnect. The words don't mix letter by letter.
  2. A terrible network. Push lost and duplicated messages to 60% and latency to 3 seconds. Lost messages are resent, duplicates are ignored, and early arrivals wait for the changes they depend on. The copies still converge.
  3. One copy goes dark. Isolate A, throw random edits at the shapes, then reconnect everyone.

The same simulator runs in the test suite, where it checks thousands of random schedules on every build.