fix(taskbar): open app window from taskbar

Shows the application window when clicking on pinned to taskbar icon, when the application has
already been opened.

fix #228

src/main/index.js

@@ -96,6 +96,8 @@ if (!gotTheLock) {
     if (mainWindow) {
       if (mainWindow.isMinimized()) {
         mainWindow.restore();
+      } else if (process.platform === 'win32') {
+        mainWindow.show();
       }
 
       mainWindow.focus();

src/main/index.spec.js

@@ -1,4 +1,4 @@
-const { app }  = require('electron');
+const { app, BrowserWindow }  = require('electron');
 const chai = require('chai');
 const sinon = require('sinon');
 const sinonChai = require('sinon-chai');
@@ -47,4 +47,18 @@ describe('App', () => {
 
     expect(app.setAppUserModelId).to.have.been.calledWith(pkgJson.build.appId);
   });
+
+  it('should call mainWindow.show when app is opened from taskbar in win32', () => {
+    app.requestSingleInstanceLock.returns(true);
+    require('./');
+
+    Object.defineProperty(process, 'platform', {
+      value: 'win32',
+    });
+    sandbox.spy(BrowserWindow.prototype, 'show');
+    sandbox.stub(BrowserWindow.prototype, 'isMinimized').returns(false);
+    app.emit('second-instance');
+
+    expect(BrowserWindow.prototype.show).to.have.been.called;
+  });
 });