Fix: make createPageYDoc return blank doc to preserve Yjs IDs on bootstrap

- createPageYDoc() now returns a blank Y.Doc instead of pre-initializing
  shared types (page, noteIds, arrowIds, nextZIndex, notes, arrows)
- getNoteIds(), getArrowIds(), getNextZIndex() lazily create missing structures
- This ensures server bootstrap updates recreate the exact original shared types
  with their original Yjs IDs, fixing the disappearing notes on refresh bug
- Updated undo-redo.ts to eagerly create lazy structures before UndoManager
  to avoid polluting the undo stack with initialization mutations
- All 57 test files (318 tests) pass

Author: gustavotoyota

new-deepnotes/apps/web/src/features/spatial/undo-redo.ts

@@ -1,5 +1,5 @@
 import * as Y from "yjs";
-import { getNotesMap, getArrowsMap, getPageMap } from "@deepnotes/collab-wire";
+import { getNotesMap, getArrowsMap, getPageMap, getNoteIds, getArrowIds, getNextZIndex } from "@deepnotes/collab-wire";
 
 export type SpatialUndoRedo = ReturnType<typeof useSpatialUndoRedo>;
 
@@ -21,6 +21,12 @@ function addTypeToScope(um: Y.UndoManager, type: Y.AbstractType<any>): void {
 }
 
 export function useSpatialUndoRedo(ydoc: Y.Doc) {
+  // Eagerly create lazy structures so they don't appear as undoable
+  // mutations when useSpatialPage first accesses them.
+  getNoteIds(ydoc);
+  getArrowIds(ydoc);
+  getNextZIndex(ydoc);
+
   const notesMap = getNotesMap(ydoc);
   const arrowsMap = getArrowsMap(ydoc);
   const pageMap = getPageMap(ydoc);

new-deepnotes/packages/collab-wire/src/page-doc-schema.test.ts

@@ -22,14 +22,10 @@ import {
 } from "./page-doc-schema.js";
 
 describe("page-doc-schema", () => {
-  it("creates a doc with empty page, notes, and arrows maps", () => {
+  it("creates a blank doc", () => {
     const ydoc = createPageYDoc();
 
-    const page = ydoc.getMap(YPAGE_KEY.page);
-    expect(page.get(YPAGE_PAGE_KEY.noteIds)).toBeInstanceOf(Y.Array);
-    expect(page.get(YPAGE_PAGE_KEY.arrowIds)).toBeInstanceOf(Y.Array);
-    expect(page.get(YPAGE_PAGE_KEY.nextZIndex)).toBe(0);
-
+    expect(ydoc.getMap(YPAGE_KEY.page).size).toBe(0);
     expect(ydoc.getMap(YPAGE_KEY.notes).size).toBe(0);
     expect(ydoc.getMap(YPAGE_KEY.arrows).size).toBe(0);
   });

new-deepnotes/packages/collab-wire/src/page-doc-schema.ts

@@ -177,8 +177,7 @@ export function getNoteMap(ydoc: Y.Doc, noteId: string): Y.Map<unknown> | undefi
 
 export function addNoteToPage(ydoc: Y.Doc, noteId: string): Y.Map<unknown> {
   const note = createNoteMap();
-  const page = getPageMap(ydoc);
-  const noteIds = page.get(YPAGE_PAGE_KEY.noteIds) as Y.Array<string>;
+  const noteIds = getNoteIds(ydoc);
   const notes = getNotesMap(ydoc);
 
   ydoc.transact(() => {
@@ -190,8 +189,7 @@ export function addNoteToPage(ydoc: Y.Doc, noteId: string): Y.Map<unknown> {
 }
 
 export function removeNoteFromPage(ydoc: Y.Doc, noteId: string): void {
-  const page = getPageMap(ydoc);
-  const noteIds = page.get(YPAGE_PAGE_KEY.noteIds) as Y.Array<string>;
+  const noteIds = getNoteIds(ydoc);
   const notes = getNotesMap(ydoc);
 
   ydoc.transact(() => {
@@ -239,8 +237,7 @@ export function getArrowMap(ydoc: Y.Doc, arrowId: string): Y.Map<unknown> | unde
 
 export function addArrowToPage(ydoc: Y.Doc, arrowId: string): Y.Map<unknown> {
   const arrow = createArrowMap();
-  const page = getPageMap(ydoc);
-  const arrowIds = page.get(YPAGE_PAGE_KEY.arrowIds) as Y.Array<string>;
+  const arrowIds = getArrowIds(ydoc);
   const arrows = getArrowsMap(ydoc);
 
   ydoc.transact(() => {
@@ -252,8 +249,7 @@ export function addArrowToPage(ydoc: Y.Doc, arrowId: string): Y.Map<unknown> {
 }
 
 export function removeArrowFromPage(ydoc: Y.Doc, arrowId: string): void {
-  const page = getPageMap(ydoc);
-  const arrowIds = page.get(YPAGE_PAGE_KEY.arrowIds) as Y.Array<string>;
+  const arrowIds = getArrowIds(ydoc);
   const arrows = getArrowsMap(ydoc);
 
   ydoc.transact(() => {
@@ -274,15 +270,33 @@ export function getPageMap(ydoc: Y.Doc): Y.Map<unknown> {
 }
 
 export function getNoteIds(ydoc: Y.Doc): Y.Array<string> {
-  return getPageMap(ydoc).get(YPAGE_PAGE_KEY.noteIds) as Y.Array<string>;
+  const page = getPageMap(ydoc);
+  let arr = page.get(YPAGE_PAGE_KEY.noteIds) as Y.Array<string> | undefined;
+  if (arr == null) {
+    arr = new Y.Array<string>();
+    page.set(YPAGE_PAGE_KEY.noteIds, arr);
+  }
+  return arr;
 }
 
 export function getArrowIds(ydoc: Y.Doc): Y.Array<string> {
-  return getPageMap(ydoc).get(YPAGE_PAGE_KEY.arrowIds) as Y.Array<string>;
+  const page = getPageMap(ydoc);
+  let arr = page.get(YPAGE_PAGE_KEY.arrowIds) as Y.Array<string> | undefined;
+  if (arr == null) {
+    arr = new Y.Array<string>();
+    page.set(YPAGE_PAGE_KEY.arrowIds, arr);
+  }
+  return arr;
 }
 
 export function getNextZIndex(ydoc: Y.Doc): number {
-  return (getPageMap(ydoc).get(YPAGE_PAGE_KEY.nextZIndex) as number) ?? 0;
+  const page = getPageMap(ydoc);
+  const val = page.get(YPAGE_PAGE_KEY.nextZIndex);
+  if (val === undefined) {
+    page.set(YPAGE_PAGE_KEY.nextZIndex, 0);
+    return 0;
+  }
+  return (val as number) ?? 0;
 }
 
 export function setNextZIndex(ydoc: Y.Doc, value: number): void {
@@ -294,18 +308,9 @@ export function setNextZIndex(ydoc: Y.Doc, value: number): void {
 // ------------------------------------------------------------------
 
 export function createPageYDoc(): Y.Doc {
-  const ydoc = new Y.Doc();
-
-  const page = ydoc.getMap(YPAGE_KEY.page);
-  page.set(YPAGE_PAGE_KEY.noteIds, new Y.Array<string>());
-  page.set(YPAGE_PAGE_KEY.arrowIds, new Y.Array<string>());
-  page.set(YPAGE_PAGE_KEY.nextZIndex, 0);
-
-  // Ensure top-level maps exist so observers can subscribe immediately.
-  ydoc.getMap(YPAGE_KEY.notes);
-  ydoc.getMap(YPAGE_KEY.arrows);
-
-  return ydoc;
+  // Return a completely blank doc so server bootstrap updates recreate
+  // the exact shared types (same Yjs IDs) that the original session used.
+  return new Y.Doc();
 }
 
 // ------------------------------------------------------------------