Issue #3466743 by DYdave: Added initial automated tests for the 'AdminToolbarToolsSettingsForm'.

admin_toolbar_tools/tests/src/Functional/AdminToolbarToolsSettingsFormTest.php

+<?php
+
+namespace Drupal\Tests\admin_toolbar_tools\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Test the Admin Toolbar settings form.
+ *
+ * @group admin_toolbar
+ */
+class AdminToolbarToolsSettingsFormTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'admin_toolbar_tools',
+  ];
+
+  /**
+   * A user with access to the Admin Toolbar settings form permission.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $permissions = [
+      'access toolbar',
+      'access administration pages',
+      'administer site configuration',
+    ];
+    $this->adminUser = $this->drupalCreateUser($permissions);
+  }
+
+  /**
+   * Test backend Admin Toolbar Tools settings form fields and submission.
+   */
+  public function testAdminToolbarToolsSettingsForm(): void {
+    /** @var \Drupal\Tests\WebAssert $assert */
+    $assert = $this->assertSession();
+
+    // Log in as an admin user to test admin pages.
+    $this->drupalLogin($this->adminUser);
+
+    // Test the 'Admin Toolbar settings' page form submission and fields.
+    $this->drupalGet('admin/config/user-interface/admin-toolbar-tools');
+    $this->submitForm([], 'Save configuration');
+    $assert->pageTextContains('The configuration options have been saved.');
+  }
+
+}