Explore: Add e2e-testing with Spectron

In this patch we're creating the most basic form of end-to-end testing
using the Spectron framework. This boots the app and verifies that it
opens.

The files aren't in the right spot and the structure of the tests need
to change but this gives us an idea of how to run these tests.

desktop/app.js

@@ -73,7 +73,10 @@ module.exports = function main() {
       mainWindow.loadUrl(url);
     }
 
-    if (isDev || process.argv.includes('--devtools')) {
+    if (
+      'test' !== process.env.NODE_ENV &&
+      (isDev || process.argv.includes('--devtools'))
+    ) {
       mainWindow.openDevTools({ mode: 'detach' });
     }
 

lib/auth/index.jsx

@@ -113,6 +113,7 @@ export class Auth extends Component {
           />
 
           <button
+            id="login__login-button"
             className={submitClasses}
             onClick={isCreatingAccount ? this.onSignUp : this.onLogin}
             type="submit"

lib/test/test.js

@@ -0,0 +1,46 @@
+import 'regenerator-runtime/runtime';
+import { Application } from 'spectron';
+import electronPath from 'electron';
+import path from 'path';
+
+const app = new Application({
+  path: electronPath,
+  args: [path.join(__dirname, '..', '..')],
+});
+
+describe('E2E', () => {
+  beforeEach(async () => await app.start(), 10000);
+
+  afterEach(async () => app && app.isRunning() && (await app.stop()));
+
+  test('starts', async () => {
+    await app.client.waitUntilWindowLoaded();
+    expect(app.isRunning()).toEqual(true);
+  });
+
+  test('logs in', async () => {
+    await app.client.waitUntilWindowLoaded();
+
+    const username = app.client.$('#login__field-username');
+    const password = app.client.$('#login__field-password');
+
+    if (!username.isExisting()) {
+      await username.waitForExist();
+    }
+
+    if (!password.isExisting()) {
+      await password.waitForExist();
+    }
+
+    username.setValue(process.env.TEST_USERNAME);
+    password.setValue(process.env.TEST_PASSWORD);
+
+    await new Promise(resolve => setTimeout(resolve, 500));
+
+    await app.client.$('#login__login-button').click();
+
+    await app.client.waitUntilWindowLoaded();
+    await new Promise(resolve => setTimeout(resolve, 5000));
+    expect(await app.client.$('.simplenote-app').isExisting()).toEqual(true);
+  });
+});