feat(desktop): add spellcheck setting

src-tauri/src/desktop/settings.rs

@@ -8,12 +8,14 @@ pub struct DesktopSettings {
     pub close_to_background_on_close: bool,
     pub show_system_tray_icon: bool,
     pub use_custom_title_bar: bool,
+    pub spellcheck: bool,
 }
 
 pub(crate) const DESKTOP_SETTINGS_PATH: &str = "desktop-preferences.json";
 pub(crate) const CLOSE_TO_BACKGROUND_ON_CLOSE_KEY: &str = "closeToBackgroundOnClose";
 pub(crate) const SHOW_SYSTEM_TRAY_ICON_KEY: &str = "showSystemTrayIcon";
 pub(crate) const USE_CUSTOM_TITLE_BAR_KEY: &str = "useCustomTitleBar";
+pub(crate) const SPELLCHECK_KEY: &str = "spellcheck";
 pub(crate) const LEGACY_KEEP_BACKGROUND_RUNNING_KEY: &str = "keepBackgroundRunning";
 
 pub(crate) const fn use_custom_title_bar_default() -> bool {
@@ -28,13 +30,15 @@ pub(crate) fn desktop_settings_from_values(
     close_to_background_on_close: Option<bool>,
     show_system_tray_icon: Option<bool>,
     use_custom_title_bar: Option<bool>,
+    spellcheck: Option<bool>,
     keep_background_running: Option<bool>,
 ) -> DesktopSettings {
     DesktopSettings {
         close_to_background_on_close: close_to_background_on_close.unwrap_or(true)
             || keep_background_running.unwrap_or(false),
         show_system_tray_icon: show_system_tray_icon.unwrap_or(true),
         use_custom_title_bar: use_custom_title_bar.unwrap_or(use_custom_title_bar_default()),
+        spellcheck: spellcheck.unwrap_or(true),
     }
 }
 
@@ -50,6 +54,7 @@ mod tests {
             close_to_background_on_close: true,
             show_system_tray_icon: false,
             use_custom_title_bar: true,
+            spellcheck: false,
         };
 
         assert_eq!(
@@ -58,6 +63,7 @@ mod tests {
                 "closeToBackgroundOnClose": true,
                 "showSystemTrayIcon": false,
                 "useCustomTitleBar": true,
+                "spellcheck": false,
             })
         );
     }
@@ -69,12 +75,14 @@ mod tests {
                 "closeToBackgroundOnClose": true,
                 "showSystemTrayIcon": false,
                 "useCustomTitleBar": true,
+                "spellcheck": false,
             }))
             .unwrap(),
             DesktopSettings {
                 close_to_background_on_close: true,
                 show_system_tray_icon: false,
                 use_custom_title_bar: true,
+                spellcheck: false,
             }
         );
     }
@@ -87,38 +95,48 @@ mod tests {
         assert!(output.contains("closeToBackgroundOnClose: boolean"));
         assert!(output.contains("showSystemTrayIcon: boolean"));
         assert!(output.contains("useCustomTitleBar: boolean"));
+        assert!(output.contains("spellcheck: boolean"));
         assert!(!output.contains("keepBackgroundRunning: boolean"));
     }
 
     #[test]
     fn legacy_background_setting_keeps_close_behavior_enabled() {
         assert_eq!(
-            desktop_settings_from_values(Some(false), Some(false), Some(false), Some(true)),
+            desktop_settings_from_values(Some(false), Some(false), Some(false), None, Some(true)),
             DesktopSettings {
                 close_to_background_on_close: true,
                 show_system_tray_icon: false,
                 use_custom_title_bar: false,
+                spellcheck: true,
             }
         );
     }
 
     #[test]
     fn explicit_close_setting_stays_disabled_when_legacy_background_is_off() {
         assert_eq!(
-            desktop_settings_from_values(Some(false), Some(true), Some(true), Some(false)),
+            desktop_settings_from_values(Some(false), Some(true), Some(true), None, Some(false)),
             DesktopSettings {
                 close_to_background_on_close: false,
                 show_system_tray_icon: true,
                 use_custom_title_bar: true,
+                spellcheck: true,
             }
         );
     }
 
     #[test]
     fn missing_custom_title_bar_setting_uses_platform_default() {
         assert_eq!(
-            desktop_settings_from_values(Some(true), Some(true), None, None).use_custom_title_bar,
+            desktop_settings_from_values(Some(true), Some(true), None, None, None)
+                .use_custom_title_bar,
             cfg!(target_os = "windows")
         );
     }
+
+    #[test]
+    fn missing_spellcheck_setting_defaults_to_enabled() {
+        assert!(desktop_settings_from_values(None, None, None, None, None).spellcheck);
+        assert!(!desktop_settings_from_values(None, None, None, Some(false), None).spellcheck);
+    }
 }

src-tauri/src/desktop/tray.rs

@@ -4,7 +4,8 @@ use crate::desktop::runtime_state::DesktopRuntimeState;
 use crate::desktop::settings::{
     desktop_settings_from_values, tray_available_for_session, use_custom_title_bar_default,
     DesktopSettings, CLOSE_TO_BACKGROUND_ON_CLOSE_KEY, DESKTOP_SETTINGS_PATH,
-    LEGACY_KEEP_BACKGROUND_RUNNING_KEY, SHOW_SYSTEM_TRAY_ICON_KEY, USE_CUSTOM_TITLE_BAR_KEY,
+    LEGACY_KEEP_BACKGROUND_RUNNING_KEY, SHOW_SYSTEM_TRAY_ICON_KEY, SPELLCHECK_KEY,
+    USE_CUSTOM_TITLE_BAR_KEY,
 };
 use serde_json::json;
 use tauri::{
@@ -26,6 +27,7 @@ pub struct DesktopSettingsState {
     close_to_background_on_close: AtomicBool,
     show_system_tray_icon: AtomicBool,
     use_custom_title_bar: AtomicBool,
+    spellcheck: AtomicBool,
     tray_available: AtomicBool,
 }
 
@@ -35,6 +37,7 @@ impl Default for DesktopSettingsState {
             close_to_background_on_close: AtomicBool::new(true),
             show_system_tray_icon: AtomicBool::new(true),
             use_custom_title_bar: AtomicBool::new(use_custom_title_bar_default()),
+            spellcheck: AtomicBool::new(true),
             tray_available: AtomicBool::new(false),
         }
     }
@@ -98,6 +101,7 @@ pub(crate) fn load_desktop_settings(
                 USE_CUSTOM_TITLE_BAR_KEY.into(),
                 json!(use_custom_title_bar_default()),
             ),
+            (SPELLCHECK_KEY.into(), json!(true)),
         ]))
         .build()
         .map_err(|error| tauri::Error::PluginInitialization("store".into(), error.to_string()))?;
@@ -112,6 +116,7 @@ pub(crate) fn load_desktop_settings(
         store
             .get(USE_CUSTOM_TITLE_BAR_KEY)
             .and_then(|value| value.as_bool()),
+        store.get(SPELLCHECK_KEY).and_then(|value| value.as_bool()),
         store
             .get(LEGACY_KEEP_BACKGROUND_RUNNING_KEY)
             .and_then(|value| value.as_bool()),
@@ -124,6 +129,7 @@ fn current_desktop_settings(app: &AppHandle<crate::BrowserEngine>) -> DesktopSet
         close_to_background_on_close: state.close_to_background_on_close.load(Ordering::Relaxed),
         show_system_tray_icon: state.show_system_tray_icon.load(Ordering::Relaxed),
         use_custom_title_bar: state.use_custom_title_bar.load(Ordering::Relaxed),
+        spellcheck: state.spellcheck.load(Ordering::Relaxed),
     }
 }
 
@@ -171,6 +177,9 @@ fn apply_desktop_settings(
     state
         .use_custom_title_bar
         .store(settings.use_custom_title_bar, Ordering::Relaxed);
+    state
+        .spellcheck
+        .store(settings.spellcheck, Ordering::Relaxed);
 
     apply_main_window_title_bar_settings(app, settings)?;
 
@@ -395,6 +404,7 @@ mod tests {
             close_to_background_on_close: true,
             show_system_tray_icon: true,
             use_custom_title_bar: false,
+            spellcheck: true,
         };
 
         assert_eq!(
@@ -409,6 +419,7 @@ mod tests {
             show_system_tray_icon: true,
             close_to_background_on_close: false,
             use_custom_title_bar: false,
+            spellcheck: true,
         };
 
         assert_eq!(
@@ -423,6 +434,7 @@ mod tests {
             close_to_background_on_close: true,
             show_system_tray_icon: true,
             use_custom_title_bar: false,
+            spellcheck: true,
         };
 
         assert!(!tray_available_for_session(settings, false));
@@ -451,6 +463,7 @@ mod tests {
             close_to_background_on_close: true,
             show_system_tray_icon: true,
             use_custom_title_bar: false,
+            spellcheck: true,
         };
 
         assert_eq!(
@@ -462,35 +475,38 @@ mod tests {
     #[test]
     fn missing_store_values_default_to_enabled() {
         assert_eq!(
-            desktop_settings_from_values(None, None, None, None),
+            desktop_settings_from_values(None, None, None, None, None),
             DesktopSettings {
                 close_to_background_on_close: true,
                 show_system_tray_icon: true,
                 use_custom_title_bar: use_custom_title_bar_default(),
+                spellcheck: true,
             }
         );
     }
 
     #[test]
     fn legacy_background_store_value_migrates_to_close_behavior() {
         assert_eq!(
-            desktop_settings_from_values(Some(false), Some(false), Some(false), Some(true)),
+            desktop_settings_from_values(Some(false), Some(false), Some(false), None, Some(true)),
             DesktopSettings {
                 close_to_background_on_close: true,
                 show_system_tray_icon: false,
                 use_custom_title_bar: false,
+                spellcheck: true,
             }
         );
     }
 
     #[test]
     fn explicit_store_values_are_preserved_when_legacy_background_is_off() {
         assert_eq!(
-            desktop_settings_from_values(Some(false), Some(false), Some(true), Some(false)),
+            desktop_settings_from_values(Some(false), Some(false), Some(true), None, Some(false)),
             DesktopSettings {
                 show_system_tray_icon: false,
                 close_to_background_on_close: false,
                 use_custom_title_bar: true,
+                spellcheck: true,
             }
         );
     }

src-tauri/src/lib.rs

@@ -540,6 +540,7 @@ mod tests {
             close_to_background_on_close: true,
             show_system_tray_icon: true,
             use_custom_title_bar: false,
+            spellcheck: true,
         };
         let _ = crate::desktop::runtime_state::DesktopRuntimeState {
             tray_available: true,

src/app/components/app-shell/AppShell.tsx

@@ -6,6 +6,7 @@ import { QueryClientProvider } from '@tanstack/react-query';
 import { isTauri } from '@tauri-apps/api/core';
 import { type as osType } from '@tauri-apps/plugin-os';
 
+import { DesktopSpellcheck } from '$components/tauri/DesktopSpellcheck';
 import { TauriFrontendReady } from '$components/tauri/TauriFrontendReady';
 import { TauriWindowFocus } from '$components/tauri/TauriWindowFocus';
 import { DesktopTitleBar } from '$components/tauri/DesktopTitleBar';
@@ -89,6 +90,7 @@ function AppShellFrame({ children, portalContainer, onPortalContainerChange }: A
     <>
       <TauriFrontendReady />
       <TauriWindowFocus />
+      <DesktopSpellcheck />
       <div
         style={{
           display: 'flex',

src/app/components/tauri/DesktopSpellcheck.test.tsx

@@ -0,0 +1,66 @@
+import { render } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { DesktopSpellcheck } from './DesktopSpellcheck';
+
+const { mockIsDesktopTauri, mockUseDesktopSetting } = vi.hoisted(() => ({
+  mockIsDesktopTauri: vi.fn<() => boolean>(),
+  mockUseDesktopSetting: vi.fn<() => readonly [boolean, (value: boolean) => void]>(),
+}));
+
+vi.mock('$utils/platform', () => ({
+  isDesktopTauri: mockIsDesktopTauri,
+}));
+
+vi.mock('$state/hooks/desktopSettings', () => ({
+  useDesktopSetting: mockUseDesktopSetting,
+}));
+
+describe('DesktopSpellcheck', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockUseDesktopSetting.mockReturnValue([true, vi.fn<(value: boolean) => void>()]);
+  });
+
+  afterEach(() => {
+    document.body.removeAttribute('spellcheck');
+  });
+
+  it('disables inherited spellcheck on the body when the setting is off', () => {
+    mockIsDesktopTauri.mockReturnValue(true);
+    mockUseDesktopSetting.mockReturnValue([false, vi.fn<(value: boolean) => void>()]);
+
+    render(<DesktopSpellcheck />);
+
+    expect(document.body.spellcheck).toBe(false);
+  });
+
+  it('keeps inherited spellcheck enabled on the body when the setting is on', () => {
+    mockIsDesktopTauri.mockReturnValue(true);
+
+    render(<DesktopSpellcheck />);
+
+    expect(document.body.spellcheck).toBe(true);
+  });
+
+  it('follows setting changes after mount', () => {
+    mockIsDesktopTauri.mockReturnValue(true);
+    mockUseDesktopSetting.mockReturnValue([true, vi.fn<(value: boolean) => void>()]);
+
+    const { rerender } = render(<DesktopSpellcheck />);
+    expect(document.body.spellcheck).toBe(true);
+
+    mockUseDesktopSetting.mockReturnValue([false, vi.fn<(value: boolean) => void>()]);
+    rerender(<DesktopSpellcheck />);
+
+    expect(document.body.spellcheck).toBe(false);
+  });
+
+  it('does not touch the body outside desktop Tauri builds', () => {
+    mockIsDesktopTauri.mockReturnValue(false);
+    mockUseDesktopSetting.mockReturnValue([false, vi.fn<(value: boolean) => void>()]);
+
+    render(<DesktopSpellcheck />);
+
+    expect(document.body.hasAttribute('spellcheck')).toBe(false);
+  });
+});

src/app/components/tauri/DesktopSpellcheck.tsx

@@ -0,0 +1,16 @@
+import { useEffect } from 'react';
+import { isDesktopTauri } from '$utils/platform';
+import { useDesktopSetting } from '$state/hooks/desktopSettings';
+
+// Editable fields inherit their spellcheck state from <body>, so a single
+// attribute governs the composer and every text input.
+export function DesktopSpellcheck() {
+  const [spellcheck] = useDesktopSetting('spellcheck');
+
+  useEffect(() => {
+    if (!isDesktopTauri()) return;
+    document.body.spellcheck = spellcheck;
+  }, [spellcheck]);
+
+  return null;
+}