Create get-app-name module that returns correct application name

Before, in order to retrieve the application name, Electron's
`getName()` method was used (https://electronjs.org/docs/api/app#appgetname).

Now, instead, we also use the Atom version in order to calculate the release
channel and be able to have it on the app name (e.g `Atom Nightly`).

spec/main-process/atom-window.test.js

@@ -97,7 +97,7 @@ describe('AtomWindow', function() {
       const { browserWindow } = w;
 
       assert.isFalse(browserWindow.isVisible());
-      assert.strictEqual(browserWindow.getTitle(), 'Atom');
+      assert.isTrue(browserWindow.getTitle().startsWith('Atom'));
 
       const settings = JSON.parse(browserWindow.loadSettingsJSON);
       assert.strictEqual(settings.userSettings, 'stub-config');

src/main-process/atom-window.js

@@ -1,4 +1,5 @@
 const { BrowserWindow, app, dialog, ipcMain } = require('electron');
+const getAppName = require('./get-app-name');
 const path = require('path');
 const url = require('url');
 const { EventEmitter } = require('events');
@@ -35,7 +36,7 @@ module.exports = class AtomWindow extends EventEmitter {
 
     const options = {
       show: false,
-      title: app.getName(),
+      title: getAppName(),
       tabbingIdentifier: 'atom',
       webPreferences: {
         // Prevent specs from throttling when the window is in the background:
@@ -80,7 +81,7 @@ module.exports = class AtomWindow extends EventEmitter {
 
     this.loadSettings = Object.assign({}, settings);
     this.loadSettings.appVersion = app.getVersion();
-    this.loadSettings.appName = app.getName();
+    this.loadSettings.appName = getAppName();
     this.loadSettings.resourcePath = this.resourcePath;
     this.loadSettings.atomHome = process.env.ATOM_HOME;
     if (this.loadSettings.devMode == null) this.loadSettings.devMode = false;

src/main-process/get-app-name.js

@@ -0,0 +1,15 @@
+const { app } = require('electron');
+const getReleaseChannel = require('../get-release-channel');
+
+module.exports = function getAppName() {
+  const releaseChannel = getReleaseChannel(app.getVersion());
+  const appNameParts = [app.getName()];
+
+  if (releaseChannel !== 'stable') {
+    appNameParts.push(
+      releaseChannel.charAt(0).toUpperCase() + releaseChannel.slice(1)
+    );
+  }
+
+  return appNameParts.join(' ');
+};

src/main-process/squirrel-update.js

@@ -1,5 +1,6 @@
 let setxPath;
 const fs = require('fs-plus');
+const getAppName = require('./get-app-name');
 const path = require('path');
 const Spawner = require('./spawner');
 const WinShell = require('./win-shell');
@@ -182,25 +183,27 @@ exports.restartAtom = app => {
 // Handle squirrel events denoted by --squirrel-* command line arguments.
 exports.handleStartupEvent = (app, squirrelCommand) => {
   const exeName = getExeName(app);
+  const appName = getAppName();
+
   switch (squirrelCommand) {
     case '--squirrel-install':
       createShortcuts(exeName, ['Desktop', 'StartMenu'], () =>
         addCommandsToPath(exeName, () =>
-          WinShell.registerShellIntegration(app.getName(), () => app.quit())
+          WinShell.registerShellIntegration(appName, () => app.quit())
         )
       );
       return true;
     case '--squirrel-updated':
-      updateShortcuts(app.getName(), exeName, () =>
+      updateShortcuts(appName, exeName, () =>
         addCommandsToPath(exeName, () =>
-          WinShell.updateShellIntegration(app.getName(), () => app.quit())
+          WinShell.updateShellIntegration(appName, () => app.quit())
         )
       );
       return true;
     case '--squirrel-uninstall':
       removeShortcuts(exeName, () =>
         removeCommandsFromPath(() =>
-          WinShell.deregisterShellIntegration(app.getName(), () => app.quit())
+          WinShell.deregisterShellIntegration(appName, () => app.quit())
         )
       );
       return true;

src/main-process/win-shell.js

@@ -1,5 +1,6 @@
 const Registry = require('winreg');
 const Path = require('path');
+const getAppName = require('./get-app-name');
 
 let exeName = Path.basename(process.execPath);
 let appPath = `"${process.execPath}"`;
@@ -136,6 +137,7 @@ function deregisterShellIntegration(appName, callback) {
 }
 
 module.exports = {
+  appName: getAppName(),
   registerShellIntegration,
   updateShellIntegration,
   deregisterShellIntegration