[MM-36456] Add support for Gnome's do-not-disturb (#2278)

* Add support for gnome do-not-disturb mode

* Add tests

* Invert condition

src/main/notifications/index.test.js

@@ -2,6 +2,7 @@
 // See LICENSE.txt for license information.
 
 'use strict';
+import cp from 'child_process';
 
 import {Notification, shell} from 'electron';
 
@@ -15,10 +16,16 @@ import {localizeMessage} from 'main/i18nManager';
 
 import WindowManager from '../windows/windowManager';
 
+import getLinuxDoNotDisturb from './dnd-linux';
+
 import {displayMention, displayDownloadCompleted, currentNotifications} from './index';
 
 const mentions = [];
 
+jest.mock('child_process', () => ({
+    execSync: jest.fn(),
+}));
+
 jest.mock('electron', () => {
     class NotificationMock {
         static isSupported = jest.fn();
@@ -231,4 +238,23 @@ describe('main/notifications', () => {
             expect(shell.showItemInFolder).toHaveBeenCalledWith('/path/to/file');
         });
     });
+
+    describe('getLinuxDoNotDisturb', () => {
+        it('should return false', () => {
+            cp.execSync.mockReturnValue('true');
+            expect(getLinuxDoNotDisturb()).toBe(false);
+        });
+
+        it('should return false if error is thrown', () => {
+            cp.execSync.mockImplementation(() => {
+                throw Error('error');
+            });
+            expect(getLinuxDoNotDisturb()).toBe(false);
+        });
+
+        it('should return true', () => {
+            cp.execSync.mockReturnValue('false');
+            expect(getLinuxDoNotDisturb()).toBe(true);
+        });
+    });
 });