Resolve #3506416 "Write functiona javascript tests"

Closes #3506416

tests/src/Functional/FluidUIAdminPagesTest.php

+<?php
+
+namespace Drupal\Tests\fluidui\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+use Drupal\node\Entity\Node;
+
+/**
+ * Tests the FluidUI Admin Pages and the Home Page.
+ *
+ * @group fluidui
+ */
+class FluidUIAdminPagesTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array<string>
+   */
+  protected static $modules = ['fluidui', 'node'];
+
+  /**
+   * Theme to enable.
+   *
+   * @var string
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Disable strict config schema.
+   *
+   * @var bool
+   */
+  protected $strictConfigSchema = FALSE;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    // Make sure to complete the normal setup steps first.
+    parent::setUp();
+
+    // Log in an administrative user.
+    $this->drupalLogin($this->rootUser);
+  }
+
+  /**
+   * Tests if user can load the front page among other things.
+   */
+  public function testLoadSite() {
+    // Load the front page.
+    $this->drupalGet('<front>');
+
+    // Confirm that the site didn't throw a server error or something else.
+    $this->assertSession()->statusCodeEquals(200);
+  }
+
+  /**
+   * Tests the admin page.
+   */
+  public function testAdminPage() {
+    $this->drupalGet('admin/config/fluidui/adminsettings');
+
+    $session = $this->assertSession();
+    $session->statusCodeEquals(200);
+    $session->pageTextContains('Enter the list of pages where the toolbox will not be displayed. Specify pages by using their paths. Enter one path per line.');
+    $session->pageTextContains('Hide the toolbox on these pages');
+    $session->pageTextContains('Display preferences toolbox on admin pages');
+
+    $this->createContentType(['type' => 'page']);
+
+    Node::create(
+          [
+            'title' => $this->randomString(),
+            'type' => 'page',
+            'body' => "Loremp",
+          ]
+      )->save();
+
+    // Add the newly created page in the blacklist.
+    $edit = [
+      'url_blacklist' => '/node/1',
+    ];
+
+    $this->submitForm($edit, 'Save configuration');
+    $session->statusCodeEquals(200);
+    $session->pageTextContains('The configuration options have been saved.');
+  }
+
+}