Issue #2613378 by chegor: Add basic test

src/Tests/AdminToolbarAlterTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\admin_toolbar\Tests\AdminToolbarAlterTest.
+ */
+
+namespace Drupal\admin_toolbar\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Test the existence of Admin Toolbar module.
+ *
+ * @group admin_toolbar
+ */
+class AdminToolbarAlterTest extends WebTestBase {
+
+  /**
+   * A user with permission to access the administrative toolbar.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('toolbar', 'admin_toolbar', 'admin_toolbar_tools');
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create an administrative user and log it in.
+    $this->adminUser = $this->drupalCreateUser(array('access toolbar'));
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Tests for a the hover of sub menus.
+   */
+  function testAdminToolbar() {
+    // Get the front page.
+    $this->drupalGet('<front>');
+    $this->assertResponse(200);
+
+    // Assert that expanded links are present in HTML.
+    // Test with the uninstall link that must be there whatever modules exists.
+    $this->assertRaw('id="toolbar-link-system-modules_uninstall"');
+
+    // Test for admin_toolbar_tools if special menu items are added.
+    $this->assertRaw('id="toolbar-link-admin_toolbar_tools-flush"');
+
+  }
+
+}