check.cjs

const Automerge = require("@automerge/automerge");
const fs = require("fs");

const bytes = fs.readFileSync(process.argv[2]);

let doc = Automerge.load(bytes);

let msg;
let peer = Automerge.init();
let docSync = Automerge.initSyncState();
let peerSync = Automerge.initSyncState();

do {
  if (msg) {
    [doc, docSync, msg] = Automerge.receiveSyncMessage(doc, docSync, msg);
  }

  [docSync, msg] = Automerge.generateSyncMessage(doc, docSync);
  if (!msg) {
    break;
  }
  [peer, peerSync] = Automerge.receiveSyncMessage(peer, peerSync, msg);
  [peerSync, msg] = Automerge.generateSyncMessage(peer, peerSync);

  console.log("syncing");
} while (msg);

Automerge.load(Automerge.save(peer));

check.go

package main

import (
	"log"
	"os"

	"github.com/automerge/automerge-go"
	"github.com/davecgh/go-spew/spew"
)

func main() {
	data, err := os.ReadFile(os.Args[1])
	if err != nil {
		panic(err)
	}
	doc, err := automerge.Load(data)
	if err != nil {
		panic(err)
	}

	log.Println("doc", spew.Sdump(doc.RootMap()))

	changes, err := doc.Changes()
	if err != nil {
		panic(err)
	}

	log.Println("changes", len(changes))

	docSync := automerge.NewSyncState(doc)
	peerDoc := automerge.New()
	peerSync := automerge.NewSyncState(peerDoc)
	var msg []byte

	for {
		if msg != nil {
			if err := docSync.ReceiveMessage(msg); err != nil {
				panic(err)
			}
		}

		msg, _ = docSync.GenerateMessage()
		if err != nil {
			panic(err)
		}

		if msg == nil {
			break
		}

		if err := peerSync.ReceiveMessage(msg); err != nil {
			panic(err)
		}

		msg, _ = peerSync.GenerateMessage()
	}

	log.Println("peer", spew.Sdump(peerDoc.RootMap()))

	reloaded, err := automerge.Load(peerDoc.Save())
	if err != nil {
		panic(err)
	}
	log.Println("reloaded peer", spew.Sdump(reloaded.RootMap()))
}