feat: add Git diff preload toggle in Settings and respect it in diff loading

src-tauri/src/types.rs

@@ -406,6 +406,8 @@ pub(crate) struct AppSettings {
         rename = "notificationSoundsEnabled"
     )]
     pub(crate) notification_sounds_enabled: bool,
+    #[serde(default = "default_preload_git_diffs", rename = "preloadGitDiffs")]
+    pub(crate) preload_git_diffs: bool,
     #[serde(
         default = "default_experimental_collab_enabled",
         rename = "experimentalCollabEnabled"
@@ -592,6 +594,10 @@ fn default_notification_sounds_enabled() -> bool {
     true
 }
 
+fn default_preload_git_diffs() -> bool {
+    true
+}
+
 fn default_experimental_collab_enabled() -> bool {
     false
 }
@@ -752,6 +758,7 @@ impl Default for AppSettings {
             code_font_family: default_code_font_family(),
             code_font_size: default_code_font_size(),
             notification_sounds_enabled: true,
+            preload_git_diffs: default_preload_git_diffs(),
             experimental_collab_enabled: false,
             experimental_collaboration_modes_enabled: false,
             experimental_steer_enabled: false,
@@ -849,6 +856,7 @@ mod tests {
         assert!(settings.code_font_family.contains("SF Mono"));
         assert_eq!(settings.code_font_size, 11);
         assert!(settings.notification_sounds_enabled);
+        assert!(settings.preload_git_diffs);
         assert!(!settings.experimental_steer_enabled);
         assert!(!settings.dictation_enabled);
         assert_eq!(settings.dictation_model_id, "base");

src/App.tsx

@@ -341,6 +341,7 @@ function MainApp() {
     activeWorkspaceRef,
   } = useGitPanelController({
     activeWorkspace,
+    gitDiffPreloadEnabled: appSettings.preloadGitDiffs,
     isCompact,
     isTablet,
     activeTab,

src/features/app/hooks/useGitPanelController.test.tsx

@@ -0,0 +1,130 @@
+// @vitest-environment jsdom
+import { act, renderHook } from "@testing-library/react";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { WorkspaceInfo } from "../../../types";
+import { useGitPanelController } from "./useGitPanelController";
+
+const useGitDiffsMock = vi.fn();
+const useGitStatusMock = vi.fn();
+const useGitLogMock = vi.fn();
+const useGitCommitDiffsMock = vi.fn();
+
+vi.mock("../../git/hooks/useGitDiffs", () => ({
+  useGitDiffs: (...args: unknown[]) => useGitDiffsMock(...args),
+}));
+
+vi.mock("../../git/hooks/useGitStatus", () => ({
+  useGitStatus: (...args: unknown[]) => useGitStatusMock(...args),
+}));
+
+vi.mock("../../git/hooks/useGitLog", () => ({
+  useGitLog: (...args: unknown[]) => useGitLogMock(...args),
+}));
+
+vi.mock("../../git/hooks/useGitCommitDiffs", () => ({
+  useGitCommitDiffs: (...args: unknown[]) => useGitCommitDiffsMock(...args),
+}));
+
+const workspace: WorkspaceInfo = {
+  id: "workspace-1",
+  name: "CodexMonitor",
+  path: "/tmp/codex-monitor",
+  connected: true,
+  settings: { sidebarCollapsed: false },
+};
+
+function makeProps(overrides?: Partial<Parameters<typeof useGitPanelController>[0]>) {
+  return {
+    activeWorkspace: workspace,
+    gitDiffPreloadEnabled: false,
+    isCompact: false,
+    isTablet: false,
+    activeTab: "codex" as const,
+    tabletTab: "codex" as const,
+    setActiveTab: vi.fn(),
+    prDiffs: [],
+    prDiffsLoading: false,
+    prDiffsError: null,
+    ...overrides,
+  };
+}
+
+function getLastEnabledArg() {
+  const { calls } = useGitDiffsMock.mock;
+  if (calls.length === 0) {
+    return undefined;
+  }
+  return calls[calls.length - 1]?.[2];
+}
+
+beforeEach(() => {
+  useGitStatusMock.mockReturnValue({
+    status: {
+      branchName: "main",
+      files: [],
+      stagedFiles: [],
+      unstagedFiles: [],
+      totalAdditions: 0,
+      totalDeletions: 0,
+    },
+    refresh: vi.fn(),
+  });
+  useGitDiffsMock.mockReturnValue({
+    diffs: [],
+    isLoading: false,
+    error: null,
+    refresh: vi.fn(),
+  });
+  useGitLogMock.mockReturnValue({
+    entries: [],
+    total: 0,
+    ahead: 0,
+    behind: 0,
+    aheadEntries: [],
+    behindEntries: [],
+    upstream: null,
+    isLoading: false,
+    error: null,
+    refresh: vi.fn(),
+  });
+  useGitCommitDiffsMock.mockReturnValue({
+    diffs: [],
+    isLoading: false,
+    error: null,
+  });
+  useGitDiffsMock.mockClear();
+});
+
+describe("useGitPanelController preload behavior", () => {
+  it("does not preload diffs when disabled and panel is hidden", () => {
+    const { result } = renderHook(() => useGitPanelController(makeProps()));
+
+    const initialEnabled = getLastEnabledArg();
+    expect(initialEnabled).toBe(true);
+
+    act(() => {
+      result.current.setGitPanelMode("issues");
+    });
+
+    const lastEnabled = getLastEnabledArg();
+    expect(lastEnabled).toBe(false);
+  });
+
+  it("loads diffs when the panel becomes visible even if preload is disabled", () => {
+    const { result } = renderHook(() => useGitPanelController(makeProps()));
+
+    act(() => {
+      result.current.setGitPanelMode("issues");
+    });
+
+    const hiddenEnabled = getLastEnabledArg();
+    expect(hiddenEnabled).toBe(false);
+
+    act(() => {
+      result.current.setGitPanelMode("diff");
+    });
+
+    const visibleEnabled = getLastEnabledArg();
+    expect(visibleEnabled).toBe(true);
+  });
+});

src/features/app/hooks/useGitPanelController.ts

@@ -7,6 +7,7 @@ import { useGitCommitDiffs } from "../../git/hooks/useGitCommitDiffs";
 
 export function useGitPanelController({
   activeWorkspace,
+  gitDiffPreloadEnabled,
   isCompact,
   isTablet,
   activeTab,
@@ -17,6 +18,7 @@ export function useGitPanelController({
   prDiffsError,
 }: {
   activeWorkspace: WorkspaceInfo | null;
+  gitDiffPreloadEnabled: boolean;
   isCompact: boolean;
   isTablet: boolean;
   activeTab: "projects" | "codex" | "git" | "log";
@@ -94,18 +96,26 @@ export function useGitPanelController({
     centerMode === "diff" ||
     (isCompact ? compactTab === "git" : gitPanelMode === "diff");
   const shouldPreloadDiffs = Boolean(
-    activeWorkspace && !preloadedWorkspaceIdsRef.current.has(activeWorkspace.id),
+    gitDiffPreloadEnabled &&
+      activeWorkspace &&
+      !preloadedWorkspaceIdsRef.current.has(activeWorkspace.id),
   );
+  const shouldLoadLocalDiffs =
+    Boolean(activeWorkspace) &&
+    (shouldPreloadDiffs ||
+      diffUiVisible ||
+      Boolean(selectedDiffPath));
   const shouldLoadDiffs =
-    Boolean(activeWorkspace) && (diffUiVisible || shouldPreloadDiffs);
+    Boolean(activeWorkspace) &&
+    (diffSource === "local" ? shouldLoadLocalDiffs : diffUiVisible);
   const shouldLoadGitLog = gitPanelMode === "log" && Boolean(activeWorkspace);
 
   const {
     diffs: gitDiffs,
     isLoading: isDiffLoading,
     error: diffError,
     refresh: refreshGitDiffs,
-  } = useGitDiffs(activeWorkspace, gitStatus.files, shouldLoadDiffs);
+  } = useGitDiffs(activeWorkspace, gitStatus.files, shouldLoadLocalDiffs);
 
   useEffect(() => {
     if (!activeWorkspace || !shouldPreloadDiffs) {

src/features/app/hooks/useSettingsModalState.ts

@@ -6,6 +6,7 @@ export type SettingsSection =
   | "dictation"
   | "shortcuts"
   | "open-apps"
+  | "git"
   | "codex"
   | "experimental";
 

src/features/settings/components/SettingsView.test.tsx

@@ -52,6 +52,7 @@ const baseSettings: AppSettings = {
     "\"SF Mono\", \"SFMono-Regular\", Menlo, Monaco, monospace",
   codeFontSize: 11,
   notificationSoundsEnabled: true,
+  preloadGitDiffs: true,
   experimentalCollabEnabled: false,
   experimentalCollaborationModesEnabled: false,
   experimentalSteerEnabled: false,

src/features/settings/components/SettingsView.tsx

@@ -8,6 +8,7 @@ import SlidersHorizontal from "lucide-react/dist/esm/icons/sliders-horizontal";
 import Mic from "lucide-react/dist/esm/icons/mic";
 import Keyboard from "lucide-react/dist/esm/icons/keyboard";
 import Stethoscope from "lucide-react/dist/esm/icons/stethoscope";
+import GitBranch from "lucide-react/dist/esm/icons/git-branch";
 import TerminalSquare from "lucide-react/dist/esm/icons/terminal-square";
 import FileText from "lucide-react/dist/esm/icons/file-text";
 import Trash2 from "lucide-react/dist/esm/icons/trash-2";
@@ -174,7 +175,8 @@ type SettingsSection =
   | "composer"
   | "dictation"
   | "shortcuts"
-  | "open-apps";
+  | "open-apps"
+  | "git";
 type CodexSection = SettingsSection | "codex" | "experimental";
 type ShortcutSettingKey =
   | "composerModelShortcut"
@@ -1036,6 +1038,14 @@ export function SettingsView({
               <ExternalLink aria-hidden />
               Open in
             </button>
+            <button
+              type="button"
+              className={`settings-nav ${activeSection === "git" ? "active" : ""}`}
+              onClick={() => setActiveSection("git")}
+            >
+              <GitBranch aria-hidden />
+              Git
+            </button>
             <button
               type="button"
               className={`settings-nav ${activeSection === "codex" ? "active" : ""}`}
@@ -2556,6 +2566,35 @@ export function SettingsView({
                 </div>
               </section>
             )}
+            {activeSection === "git" && (
+              <section className="settings-section">
+                <div className="settings-section-title">Git</div>
+                <div className="settings-section-subtitle">
+                  Manage how diffs are loaded in the Git sidebar.
+                </div>
+                <div className="settings-toggle-row">
+                  <div>
+                    <div className="settings-toggle-title">Preload git diffs</div>
+                    <div className="settings-toggle-subtitle">
+                      Make viewing git diff faster.
+                    </div>
+                  </div>
+                  <button
+                    type="button"
+                    className={`settings-toggle ${appSettings.preloadGitDiffs ? "on" : ""}`}
+                    onClick={() =>
+                      void onUpdateAppSettings({
+                        ...appSettings,
+                        preloadGitDiffs: !appSettings.preloadGitDiffs,
+                      })
+                    }
+                    aria-pressed={appSettings.preloadGitDiffs}
+                  >
+                    <span className="settings-toggle-knob" />
+                  </button>
+                </div>
+              </section>
+            )}
             {activeSection === "codex" && (
               <section className="settings-section">
                 <div className="settings-section-title">Codex</div>

src/features/settings/hooks/useAppSettings.ts

@@ -52,6 +52,7 @@ const defaultSettings: AppSettings = {
   codeFontFamily: DEFAULT_CODE_FONT_FAMILY,
   codeFontSize: CODE_FONT_SIZE_DEFAULT,
   notificationSoundsEnabled: true,
+  preloadGitDiffs: true,
   experimentalCollabEnabled: false,
   experimentalCollaborationModesEnabled: false,
   experimentalSteerEnabled: false,

src/types.ts

@@ -146,6 +146,7 @@ export type AppSettings = {
   codeFontFamily: string;
   codeFontSize: number;
   notificationSoundsEnabled: boolean;
+  preloadGitDiffs: boolean;
   experimentalCollabEnabled: boolean;
   experimentalCollaborationModesEnabled: boolean;
   experimentalSteerEnabled: boolean;