fix(super-editor): preserve root doc attrs during collaboration seeding

packages/super-editor/src/core/Editor.collaboration-seed.test.ts

@@ -0,0 +1,91 @@
+import { beforeAll, describe, expect, it } from 'vitest';
+import { Doc as YDoc } from 'yjs';
+import { Editor } from './Editor.js';
+import { getStarterExtensions } from '@extensions/index.js';
+import { getTestDataAsFileBuffer } from '@tests/helpers/helpers.js';
+
+type SyncHandler = (synced?: boolean) => void;
+
+function createProviderStub() {
+  const listeners = {
+    sync: new Set<SyncHandler>(),
+    synced: new Set<SyncHandler>(),
+  };
+
+  return {
+    synced: false,
+    isSynced: false,
+    on(event: 'sync' | 'synced', handler: SyncHandler) {
+      listeners[event].add(handler);
+    },
+    off(event: 'sync' | 'synced', handler: SyncHandler) {
+      listeners[event].delete(handler);
+    },
+    emit(event: 'sync' | 'synced', value?: boolean) {
+      for (const handler of listeners[event]) {
+        handler(value);
+      }
+    },
+  };
+}
+
+function createTestEditor(options: Partial<ConstructorParameters<typeof Editor>[0]> = {}) {
+  return new Editor({
+    isHeadless: true,
+    deferDocumentLoad: true,
+    mode: 'docx',
+    extensions: getStarterExtensions(),
+    suppressDefaultDocxStyles: true,
+    ...options,
+  });
+}
+
+describe('Editor collaboration seeding', () => {
+  let centeredBuffer: Buffer;
+
+  beforeAll(async () => {
+    centeredBuffer = await getTestDataAsFileBuffer('advanced-text.docx');
+  });
+
+  it('preserves the first paragraph attrs when seeding a collaborative room', async () => {
+    const provider = createProviderStub();
+    const ydoc = new YDoc();
+    const seededEditor = createTestEditor({
+      ydoc,
+      collaborationProvider: provider,
+    });
+    const directEditor = createTestEditor();
+
+    try {
+      await seededEditor.open(centeredBuffer, {
+        mode: 'docx',
+        isNewFile: true,
+      });
+      await directEditor.open(centeredBuffer, {
+        mode: 'docx',
+      });
+
+      provider.emit('synced', true);
+      await new Promise((resolve) => setTimeout(resolve, 0));
+
+      const seededFirstParagraph = seededEditor.state.doc.firstChild;
+      const directFirstParagraph = directEditor.state.doc.firstChild;
+
+      expect(seededFirstParagraph?.textContent).toBe(directFirstParagraph?.textContent);
+      expect(seededFirstParagraph?.attrs?.paraId).toBe(directFirstParagraph?.attrs?.paraId);
+      expect(seededFirstParagraph?.attrs?.paragraphProperties?.justification).toBe(
+        directFirstParagraph?.attrs?.paragraphProperties?.justification,
+      );
+      expect(seededFirstParagraph?.attrs?.attributes ?? null).toEqual(directFirstParagraph?.attrs?.attributes ?? null);
+    } finally {
+      if (seededEditor.lifecycleState === 'ready') {
+        seededEditor.close();
+      }
+      if (directEditor.lifecycleState === 'ready') {
+        directEditor.close();
+      }
+      seededEditor.destroy();
+      directEditor.destroy();
+    }
+  });
+});

packages/super-editor/src/core/Editor.ts

@@ -1529,6 +1529,38 @@ export class Editor extends EventEmitter<EditorEventMap> {
     this.#dispatchTransaction(tr);
   }
 
+  /**
+   * Sync root-level document attrs without mutating the first top-level node.
+   */
+  #syncDocumentAttrs(nextAttrs: Record<string, unknown> = {}): void {
+    const currentAttrs = (this.state.doc?.attrs ?? {}) as Record<string, unknown>;
+    const docAttrSpecs = (this.schema?.topNodeType?.spec?.attrs ?? {}) as Record<string, { default?: unknown }>;
+    const attrKeys = new Set([...Object.keys(docAttrSpecs), ...Object.keys(currentAttrs), ...Object.keys(nextAttrs)]);
+
+    if (attrKeys.size === 0) return;
+
+    const valuesMatch = (a: unknown, b: unknown): boolean => a === b || JSON.stringify(a) === JSON.stringify(b);
+
+    const tr = this.state.tr.setMeta('addToHistory', false);
+    let changed = false;
+
+    for (const key of attrKeys) {
+      const hasNextValue = Object.prototype.hasOwnProperty.call(nextAttrs, key);
+      const nextValue = hasNextValue ? nextAttrs[key] : docAttrSpecs[key]?.default;
+
+      if (valuesMatch(currentAttrs[key], nextValue)) {
+        continue;
+      }
+
+      tr.setDocAttribute(key, nextValue);
+      changed = true;
+    }
+
+    if (changed) {
+      this.#dispatchTransaction(tr);
+    }
+  }
+
   /**
    * Replace the current document with new data. Necessary for initializing a new collaboration file,
    * since we need to insert the data only after the provider has synced.
@@ -1547,15 +1579,7 @@ export class Editor extends EventEmitter<EditorEventMap> {
       ydoc.getMap('meta').set('bodySectPr', nextBodySectPr);
     }
 
-    if (Object.keys(doc.attrs).length > 0) {
-      const attrsTr = this.state.tr
-        .setNodeMarkup(0, undefined, {
-          ...(this.state.doc.attrs ?? {}),
-          ...(doc.attrs ?? {}),
-        })
-        .setMeta('addToHistory', false);
-      this.#dispatchTransaction(attrsTr);
-    }
+    this.#syncDocumentAttrs((doc.attrs ?? {}) as Record<string, unknown>);
 
     setTimeout(() => {
       this.#initComments();

packages/super-editor/src/core/commands/setSectionPageMarginsAtSelection.js

@@ -137,8 +137,7 @@ export const setSectionPageMarginsAtSelection =
     }
 
     // Write updated body sectPr onto the doc attrs so layout sees it immediately
-    const nextDocAttrs = { ...docAttrs, bodySectPr: sectPr };
-    tr.setNodeMarkup(0, undefined, nextDocAttrs);
+    tr.setDocAttribute('bodySectPr', sectPr);
 
     tr.setMeta('forceUpdatePagination', true);
     return true;

packages/super-editor/src/document-api-adapters/__conformance__/contract-conformance.test.ts

@@ -1356,6 +1356,7 @@ function makeSectionsEditor(options: SectionEditorOptions = {}): Editor {
       return tr;
     }),
     setNodeMarkup: vi.fn(() => tr),
+    setDocAttribute: vi.fn(() => tr),
     setMeta: vi.fn(() => tr),
     mapping: {
       maps: [] as unknown[],

packages/super-editor/src/document-api-adapters/helpers/section-mutation-wrapper.ts

@@ -106,9 +106,8 @@ export function applySectPrToProjection(editor: Editor, projection: SectionProje
     return;
   }
 
-  const docAttrs = (editor.state.doc.attrs ?? {}) as Record<string, unknown>;
   const tr = applyDirectMutationMeta(editor.state.tr);
-  tr.setNodeMarkup(0, undefined, { ...docAttrs, bodySectPr: sectPr });
+  tr.setDocAttribute('bodySectPr', sectPr);
   tr.setMeta('forceUpdatePagination', true);
   editor.dispatch(tr);
   syncConverterBodySection(editor, sectPr);

packages/super-editor/src/document-api-adapters/sections-adapter.ts

@@ -245,9 +245,8 @@ function applySectPrToProjection(editor: Editor, projection: SectionProjection,
     return;
   }
 
-  const docAttrs = (editor.state.doc.attrs ?? {}) as Record<string, unknown>;
   const tr = applyDirectMutationMeta(editor.state.tr);
-  tr.setNodeMarkup(0, undefined, { ...docAttrs, bodySectPr: sectPr });
+  tr.setDocAttribute('bodySectPr', sectPr);
   tr.setMeta('forceUpdatePagination', true);
   editor.dispatch(tr);
   syncConverterBodySection(editor, sectPr);

packages/super-editor/src/extensions/collaboration/collaboration.js

@@ -70,12 +70,8 @@ const applyBodySectPrFromMetaMap = (editor, ydoc) => {
 
   if (!editor?.state?.tr) return false;
 
-  const nextDocAttrs = {
-    ...(editor.state.doc?.attrs ?? {}),
-    bodySectPr: nextBodySectPr,
-  };
   const tr = editor.state.tr
-    .setNodeMarkup(0, undefined, nextDocAttrs)
+    .setDocAttribute('bodySectPr', nextBodySectPr)
     .setMeta('addToHistory', false)
     .setMeta(BODY_SECT_PR_SYNC_META_KEY, true);
 

packages/super-editor/src/extensions/collaboration/collaboration.test.js

@@ -213,7 +213,7 @@ describe('collaboration extension', () => {
     ydoc._maps.metas.store.set('bodySectPr', bodySectPr);
 
     const tr = {
-      setNodeMarkup: vi.fn(() => tr),
+      setDocAttribute: vi.fn(() => tr),
       setMeta: vi.fn(() => tr),
     };
     const editor = {
@@ -242,10 +242,7 @@ describe('collaboration extension', () => {
 
     ydoc._maps.metas._trigger(new Map([['bodySectPr', {}]]));
 
-    expect(tr.setNodeMarkup).toHaveBeenCalledWith(0, undefined, {
-      attributes: null,
-      bodySectPr,
-    });
+    expect(tr.setDocAttribute).toHaveBeenCalledWith('bodySectPr', bodySectPr);
     expect(tr.setMeta).toHaveBeenCalledWith('addToHistory', false);
     expect(tr.setMeta).toHaveBeenCalledWith('bodySectPrSync', true);
     expect(editor.dispatch).toHaveBeenCalledWith(tr);