cleanup: Use optional chaining and ?? operator

Those operators have been supported since gjs switched to mozjs78
last cycle. While not ground-breaking, using it makes for a nice
cleanup here and there.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1517>

js/ui/altTab.js

@@ -427,8 +427,7 @@ class CyclerHighlight extends St.Widget {
         if (this._clone.source)
             this._clone.source.sync_visibility();
 
-        let windowActor = this._window
+        const windowActor = this._window?.get_compositor_private();
-            ? this._window.get_compositor_private() : null;
 
         if (windowActor)
             windowActor.hide();
@@ -532,7 +531,7 @@ class GroupCyclerPopup extends CyclerPopup {
 
     _getWindows() {
         let app = Shell.WindowTracker.get_default().focus_app;
-        let appWindows = app ? app.get_windows() : [];
+        let appWindows = app?.get_windows() ?? [];
 
         if (this._settings.get_boolean('current-workspace-only')) {
             const workspaceManager = global.workspace_manager;

js/ui/appDisplay.js

@@ -972,7 +972,7 @@ class AppDisplay extends BaseAppView {
         this._switcherooProxy = global.get_switcheroo_control();
         if (this._switcherooProxy) {
             let prop = this._switcherooProxy.get_cached_property('HasDualGpu');
-            discreteGpuAvailable = prop ? prop.unpack() : false;
+            discreteGpuAvailable = prop?.unpack() ?? false;
         } else {
             discreteGpuAvailable = false;
         }

js/ui/components/automountManager.js

@@ -176,7 +176,7 @@ var AutomountManager = class {
         if (allowAutorun)
             this._allowAutorun(volume);
 
-        let mountOp = operation ? operation.mountOp : null;
+        const mountOp = operation?.mountOp ?? null;
         this._activeOperations.set(volume, operation);
 
         volume.mount(0, mountOp, null,
@@ -226,7 +226,7 @@ var AutomountManager = class {
 
     _reaskPassword(volume) {
         let prevOperation = this._activeOperations.get(volume);
-        let existingDialog = prevOperation ? prevOperation.borrowDialog() : null;
+        const existingDialog = prevOperation?.borrowDialog();
         let operation =
             new ShellMountOperation.ShellMountOperation(volume,
                                                         { existingDialog });

js/ui/components/networkAgent.js

@@ -793,7 +793,7 @@ var NetworkAgent = class {
         }
 
         const prop = plugin.lookup_property('GNOME', 'supports-external-ui-mode');
-        const trimmedProp = prop ? prop.trim().toLowerCase() : '';
+        const trimmedProp = prop?.trim().toLowerCase() ?? '';
 
         return {
             fileName,

js/ui/endSessionDialog.js

@@ -676,8 +676,7 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
                 let userAvatar = new UserWidget.Avatar(session.user, { iconSize: _ITEM_ICON_SIZE });
                 userAvatar.update();
 
-                userName = session.user.get_real_name()
+                userName = session.user.get_real_name() ?? session.username;
-                    ? session.user.get_real_name() : session.username;
 
                 let userLabelText;
                 if (session.remote)

js/ui/environment.js

@@ -364,7 +364,7 @@ function init() {
             this.getHours(),
             this.getMinutes(),
             this.getSeconds());
-        return dt ? dt.format(format) : '';
+        return dt?.format(format) ?? '';
     };
 
     let slowdownEnv = GLib.getenv('GNOME_SHELL_SLOWDOWN_FACTOR');

js/ui/inhibitShortcutsDialog.js

@@ -73,7 +73,7 @@ var InhibitShortcutsDialog = GObject.registerClass({
     }
 
     _buildLayout() {
-        let name = this._app ? this._app.get_name() : this._window.title;
+        const name = this._app?.get_name() ?? this._window.title;
 
         let content = new Dialog.MessageDialogContent({
             title: _('Allow inhibiting shortcuts'),

js/ui/notificationDaemon.js

@@ -124,7 +124,7 @@ var FdoNotificationDaemon = class FdoNotificationDaemon {
             return source;
         }
 
-        let appId = ndata ? ndata.hints['desktop-entry'] || null : null;
+        const appId = ndata?.hints['desktop-entry'];
         source = new FdoNotificationDaemonSource(title, pid, sender, appId);
 
         this._sources.push(source);
@@ -528,10 +528,10 @@ class GtkNotificationDaemonNotification extends MessageTray.Notification {
             });
         }
 
-        this._defaultAction = defaultAction ? defaultAction.unpack() : null;
+        this._defaultAction = defaultAction?.unpack();
         this._defaultActionTarget = defaultActionTarget;
 
-        this.update(title.unpack(), body ? body.unpack() : null,
+        this.update(title.unpack(), body?.unpack(),
                     { gicon: gicon ? Gio.icon_deserialize(gicon) : null,
                       datetime: time ? GLib.DateTime.new_from_unix_local(time.unpack()) : null });
     }

js/ui/padOsd.js

@@ -770,7 +770,7 @@ var PadOsd = GObject.registerClass({
 
     _getActionText(type, number) {
         let str = global.display.get_pad_action_label(this.padDevice, type, number);
-        return str ? str : _("None");
+        return str ?? _('None');
     }
 
     _updateActionLabels() {
@@ -887,7 +887,7 @@ var PadOsd = GObject.registerClass({
             if (this._followUpActionEdition(str))
                 return;
 
-            this._padDiagram.stopEdition(false, str ? str : _("None"));
+            this._padDiagram.stopEdition(false, str ?? _('None'));
             this._editedAction = null;
         }
 

js/ui/panel.js

@@ -143,8 +143,8 @@ class AppMenu extends PopupMenu.PopupMenu {
 
         this._updateWindowsSection();
 
-        let appInfo = app ? app.app_info : null;
+        const appInfo = app?.app_info;
-        let actions = appInfo ? appInfo.list_actions() : [];
+        const actions = appInfo?.list_actions() ?? [];
 
         this._actionSection.removeAll();
         actions.forEach(action => {

js/ui/panelMenu.js

@@ -96,11 +96,13 @@ var Button = GObject.registerClass({
     Signals: { 'menu-set': {} },
 }, class PanelMenuButton extends ButtonBox {
     _init(menuAlignment, nameText, dontCreateMenu) {
-        super._init({ reactive: true,
+        super._init({
+            reactive: true,
             can_focus: true,
             track_hover: true,
-                      accessible_name: nameText ? nameText : "",
+            accessible_name: nameText ?? '',
-                      accessible_role: Atk.Role.MENU });
+            accessible_role: Atk.Role.MENU,
+        });
 
         if (dontCreateMenu)
             this.menu = new PopupMenu.PopupDummyMenu(this);

js/ui/popupMenu.js

@@ -226,7 +226,7 @@ var PopupBaseMenuItem = GObject.registerClass({
     }
 
     getSensitive() {
-        let parentSensitive = this._parent ? this._parent.sensitive : true;
+        const parentSensitive = this._parent?.sensitive ?? true;
         return this._activatable && this._sensitive && parentSensitive;
     }
 
@@ -504,7 +504,7 @@ var PopupMenuBase = class {
     }
 
     getSensitive() {
-        let parentSensitive = this._parent ? this._parent.sensitive : true;
+        const parentSensitive = this._parent?.sensitive ?? true;
         return this._sensitive && parentSensitive;
     }
 

js/ui/search.js

@@ -873,7 +873,7 @@ var SearchResultsView = GObject.registerClass({
             return;
         }
 
-        let from = this._defaultResult ? this._defaultResult : null;
+        const from = this._defaultResult ?? null;
         this.navigate_focus(from, direction, false);
     }
 

js/ui/shellDBus.js

@@ -160,9 +160,10 @@ var GnomeShell = class {
         if (deviceNode)
             params['device-node'] = GLib.Variant.new('s', deviceNode);
 
-        connection.emit_signal(destination,
+        connection.emit_signal(
+            destination,
             this._dbusImpl.get_object_path(),
-                               info ? info.name : null,
+            info?.name ?? null,
             'AcceleratorActivated',
             GLib.Variant.new('(ua{sv})', [action, params]));
     }

js/ui/windowManager.js

@@ -891,7 +891,7 @@ var WindowManager = class {
             // FIXME: Fix num buttons
             for (let i = 0; i < 50; i++) {
                 let str = display.get_pad_action_label(pad, Meta.PadActionType.BUTTON, i);
-                labels.push(str ? str : '');
+                labels.push(str ?? '');
             }
 
             if (this._gsdWacomProxy) {

js/ui/windowPreview.js

@@ -34,7 +34,7 @@ var WindowPreviewLayout = GObject.registerClass({
 
         for (const windowInfo of this._windows.values()) {
             const frame = windowInfo.metaWindow.get_frame_rect();
-            frameRect = frameRect ? frameRect.union(frame) : frame;
+            frameRect = frameRect?.union(frame) ?? frame;
         }
 
         if (!frameRect)

js/ui/workspace.js

@@ -1291,9 +1291,7 @@ class Workspace extends St.Widget {
     }
 
     _onCloneSelected(clone, time) {
-        let wsIndex;
+        const wsIndex = this.metaWorkspace?.index();
-        if (this.metaWorkspace)
-            wsIndex = this.metaWorkspace.index();
         Main.activateWindow(clone.metaWindow, time, wsIndex);
     }
 

js/ui/xdndHandler.js

@@ -86,7 +86,7 @@ var XdndHandler = class {
         let dragEvent = {
             x,
             y,
-            dragActor: this._cursorWindowClone ? this._cursorWindowClone : this._dummy,
+            dragActor: this._cursorWindowClone ?? this._dummy,
             source: this,
             targetActor: pickedActor,
         };