perf: preserve store state on unchanged document titles (#19459)

* perf: preserve store state on unchanged document titles

* fix(browser): compare every doc-history field before skipping a title refresh

A hand-listed title check would silently swallow any field added to
WorkspaceDocHistoryEntry later. Cover the over-cap trim path too.

---------

Co-authored-by: m4air <m4air@m4airs-MacBook-Air.local>
Co-authored-by: Neil <4138956+nwparker@users.noreply.github.com>

src/renderer/src/store/slices/browser/browser-history-actions.ts

@@ -9,7 +9,8 @@ import {
 import {
   MAX_WORKSPACE_DOC_HISTORY_ENTRIES,
   normalizeWorkspaceDocHistoryEntries,
-  normalizeWorkspaceDocHistoryTitle
+  normalizeWorkspaceDocHistoryTitle,
+  workspaceDocHistoryEntriesEqual
 } from '../../../../../shared/workspace-doc-history'
 import { browserPageDocLocationsEqual } from '../../../../../shared/browser-page-doc-location'
 import { ORCA_BROWSER_BLANK_URL } from '../../../../../shared/constants'
@@ -37,16 +38,25 @@ export function createBrowserHistoryActions(
           title ?? existing?.title,
           docLocation
         )
-        const next: WorkspaceDocHistoryEntry[] = existing
-          ? s.workspaceDocHistory.map((entry) =>
-              entry === existing
-                ? {
-                    ...entry,
-                    title: normalizedTitle,
-                    ...(bump ? { lastVisitedAt: now, visitCount: entry.visitCount + 1 } : {})
-                  }
-                : entry
-            )
+        const updated: WorkspaceDocHistoryEntry | null = existing
+          ? {
+              ...existing,
+              title: normalizedTitle,
+              ...(bump ? { lastVisitedAt: now, visitCount: existing.visitCount + 1 } : {})
+            }
+          : null
+        // A repeated title-updated event from a live preview changes nothing; hand back the same
+        // state so no subscriber re-renders. Over the cap the old path still had trimming to do.
+        if (
+          existing &&
+          updated &&
+          workspaceDocHistoryEntriesEqual(updated, existing) &&
+          s.workspaceDocHistory.length <= MAX_WORKSPACE_DOC_HISTORY_ENTRIES
+        ) {
+          return s
+        }
+        const next: WorkspaceDocHistoryEntry[] = updated
+          ? s.workspaceDocHistory.map((entry) => (entry === existing ? updated : entry))
           : [
               { docLocation, title: normalizedTitle, lastVisitedAt: now, visitCount: 1 },
               ...s.workspaceDocHistory

src/renderer/src/store/slices/workspace-document-title-refresh.test.ts

@@ -0,0 +1,87 @@
+import { describe, expect, it, vi } from 'vitest'
+import { createTestStore } from './store-test-helpers'
+import { createStoreCascadesMockApi } from './store-cascades-test-harness'
+import {
+  MAX_WORKSPACE_DOC_HISTORY_ENTRIES,
+  workspaceDocHistoryEntriesEqual,
+  type WorkspaceDocHistoryEntry
+} from '../../../../shared/workspace-doc-history'
+
+createStoreCascadesMockApi()
+const WT = 'repo1::/path/wt1'
+
+describe('workspace document history title refresh', () => {
+  it('does not publish unchanged titles but preserves real visits and title changes', () => {
+    const store = createTestStore()
+    const location = {
+      kind: 'workspace-doc' as const,
+      worktreeId: WT,
+      filePath: '/path/wt1/doc.html'
+    }
+    store.getState().recordWorkspaceDocVisit(location, 'Document')
+    const history = store.getState().workspaceDocHistory
+    const listener = vi.fn()
+    const unsubscribe = store.subscribe(listener)
+    for (let i = 0; i < 200; i++) {
+      store.getState().recordWorkspaceDocVisit(location, 'Document', { bump: false })
+    }
+    expect(listener).not.toHaveBeenCalled()
+    expect(store.getState().workspaceDocHistory).toBe(history)
+    store.getState().recordWorkspaceDocVisit(location, 'Renamed', { bump: false })
+    expect(store.getState().workspaceDocHistory[0]).toEqual({ ...history[0], title: 'Renamed' })
+    store.getState().recordWorkspaceDocVisit(location, 'Renamed')
+    expect(store.getState().workspaceDocHistory[0].visitCount).toBe(2)
+    unsubscribe()
+  })
+
+  it('still trims an over-cap history that a persisted state carried in', () => {
+    const store = createTestStore()
+    const location = {
+      kind: 'workspace-doc' as const,
+      worktreeId: WT,
+      filePath: '/path/wt1/doc-0.html'
+    }
+    const overCap: WorkspaceDocHistoryEntry[] = Array.from(
+      { length: MAX_WORKSPACE_DOC_HISTORY_ENTRIES + 5 },
+      (_unused, index) => ({
+        docLocation: {
+          kind: 'workspace-doc' as const,
+          worktreeId: WT,
+          filePath: `/path/wt1/doc-${index}.html`
+        },
+        title: `Doc ${index}`,
+        lastVisitedAt: 1_000 - index,
+        visitCount: 1
+      })
+    )
+    store.setState({ workspaceDocHistory: overCap })
+
+    // The title is already current, but skipping here would strand the list above its cap forever.
+    store.getState().recordWorkspaceDocVisit(location, 'Doc 0', { bump: false })
+
+    expect(store.getState().workspaceDocHistory).toHaveLength(MAX_WORKSPACE_DOC_HISTORY_ENTRIES)
+    expect(store.getState().workspaceDocHistory[0].title).toBe('Doc 0')
+  })
+
+  it('compares every entry field, so an added field cannot be silently dropped', () => {
+    const base: WorkspaceDocHistoryEntry = {
+      docLocation: { kind: 'workspace-doc', worktreeId: WT, filePath: '/path/wt1/doc.html' },
+      title: 'Document',
+      lastVisitedAt: 10,
+      visitCount: 1
+    }
+    expect(workspaceDocHistoryEntriesEqual(base, { ...base })).toBe(true)
+    expect(workspaceDocHistoryEntriesEqual(base, { ...base, title: 'Other' })).toBe(false)
+    expect(workspaceDocHistoryEntriesEqual(base, { ...base, visitCount: 2 })).toBe(false)
+    expect(workspaceDocHistoryEntriesEqual(base, { ...base, lastVisitedAt: 11 })).toBe(false)
+    expect(
+      workspaceDocHistoryEntriesEqual(base, { ...base, docLocation: { ...base.docLocation } })
+    ).toBe(false)
+    expect(
+      workspaceDocHistoryEntriesEqual(base, {
+        ...base,
+        ...({ faviconUrl: 'x' } as Partial<WorkspaceDocHistoryEntry>)
+      })
+    ).toBe(false)
+  })
+})

src/shared/workspace-doc-history.ts

@@ -16,6 +16,21 @@ export type WorkspaceDocHistoryEntry = {
 
 export const MAX_WORKSPACE_DOC_HISTORY_ENTRIES = 100
 
+/**
+ * Shallow-equal over whatever keys an entry actually carries, rather than a hand-listed subset, so
+ * a field added to `WorkspaceDocHistoryEntry` later cannot slip past a skip-if-unchanged check.
+ */
+export function workspaceDocHistoryEntriesEqual(
+  left: WorkspaceDocHistoryEntry,
+  right: WorkspaceDocHistoryEntry
+): boolean {
+  const leftKeys = Object.keys(left) as (keyof WorkspaceDocHistoryEntry)[]
+  return (
+    leftKeys.length === Object.keys(right).length &&
+    leftKeys.every((key) => Object.is(left[key], right[key]))
+  )
+}
+
 /** The title fence the page store applies, for history rows: a url-as-title falls back to the file. */
 export function normalizeWorkspaceDocHistoryTitle(
   title: string | null | undefined,