fix(desktop): avoid redundant editor hydration

apps/web/src/components/EditorPane.tsx

@@ -222,7 +222,10 @@ import {
   ResourceActionMenu,
   type NoteLinkHintPosition,
 } from "./editor/EditorPaneChrome";
-import { resolveEditorDraftState } from "./editor/editor-draft-state";
+import {
+  resolveEditorDraftState,
+  shouldReplaceEditorDocument,
+} from "./editor/editor-draft-state";
 import type { EdgeEverPluginHost, PluginEditorAdapter } from "@/lib/plugins/plugin-host";
 import {
   useEditorResourceActions,
@@ -2212,10 +2215,14 @@ const RichEditorPane = ({
       } = resolvedDraft;
 
       const alreadyHydratedSameMemo = sameMemo && hydratedMemoIdRef.current === memo.id;
+      const currentEditorDocument = isEditorReady(currentEditor)
+        ? currentEditor.getJSON() as TiptapDoc
+        : null;
+      const shouldReplaceDocument = shouldReplaceEditorDocument(currentEditorDocument, nextContent);
       const editorMarkdownMatches = Boolean(
         alreadyHydratedSameMemo &&
-        isEditorReady(currentEditor) &&
-        docToMarkdown(currentEditor.getJSON() as TiptapDoc) === nextMarkdown &&
+        currentEditorDocument &&
+        docToMarkdown(currentEditorDocument) === nextMarkdown &&
         title === nextTitle &&
         tagsText === nextTagsText
       );
@@ -2275,7 +2282,7 @@ const RichEditorPane = ({
       setMarkdownSource(nextMarkdown);
       setMobilePlainTextElementValue(mobileTextAreaRef.current, nextMarkdown);
 
-      if (isEditorReady(currentEditor)) {
+      if (isEditorReady(currentEditor) && shouldReplaceDocument) {
         try {
           currentEditor.commands.setContent(nextContent);
         } catch (err) {

apps/web/src/components/editor/editor-draft-state.test.mjs

@@ -1,5 +1,8 @@
 import { describe, expect, test } from "bun:test";
-import { resolveEditorDraftState } from "./editor-draft-state.ts";
+import {
+  resolveEditorDraftState,
+  shouldReplaceEditorDocument,
+} from "./editor-draft-state.ts";
 
 const doc = (text) => ({ type: "doc", content: [{ type: "paragraph", content: [{ type: "text", text }] }] });
 
@@ -125,3 +128,28 @@ describe("editor draft source resolution", () => {
     expect(state.hasUnsavedChanges).toBe(false);
   });
 });
+
+describe("editor document hydration", () => {
+  test("does not replace a newly mounted empty note with the same empty document", () => {
+    const emptyDocument = { type: "doc", content: [{ type: "paragraph" }] };
+    expect(shouldReplaceEditorDocument(emptyDocument, emptyDocument)).toBe(false);
+  });
+
+  test("replaces the mounted memo when a recovered local draft has different content", () => {
+    expect(shouldReplaceEditorDocument(doc("remote body"), doc("recovered draft"))).toBe(true);
+  });
+
+  test("does not treat rich documents with the same markdown text as identical", () => {
+    const plainDocument = doc("same body");
+    const themedDocument = {
+      type: "doc",
+      content: [{ type: "edgeeverThemeBlock", attrs: { theme: "paper" }, content: plainDocument.content }],
+    };
+
+    expect(shouldReplaceEditorDocument(plainDocument, themedDocument)).toBe(true);
+  });
+
+  test("hydrates when the current editor document cannot be read", () => {
+    expect(shouldReplaceEditorDocument(null, doc("remote body"))).toBe(true);
+  });
+});

apps/web/src/components/editor/editor-draft-state.ts

@@ -24,6 +24,17 @@ export type EditorDraftState = {
   hasUnsavedChanges: boolean;
 };
 
+/**
+ * TipTap is created with the memo snapshot before the asynchronous local-draft
+ * lookup finishes. Replacing that already-identical document during hydration
+ * resets the ProseMirror view and selection, which is visible in slower desktop
+ * runtimes as a second editor paint.
+ */
+export const shouldReplaceEditorDocument = (
+  currentDocument: TiptapDoc | null,
+  nextDocument: TiptapDoc,
+) => currentDocument === null || JSON.stringify(currentDocument) !== JSON.stringify(nextDocument);
+
 type ResolveEditorDraftStateInput = {
   memo: MemoDetail;
   draft?: LocalDraft | null;