Break ground on document "persistence"

src/sync.ts

@@ -0,0 +1,15 @@
+import * as Y from 'yjs';
+
+const fakeStore = new Map<string, Uint8Array[]>();
+
+export function syncDoc(id: string, doc: Y.Doc) {
+  const updates = fakeStore.get(id) ?? [];
+  fakeStore.set(id, updates);
+  for (const update of updates) {
+    Y.applyUpdate(doc, update);
+  }
+
+  doc.on('update', (update: Uint8Array) => {
+    updates.push(update);
+  });
+}