From 2175e1f04d15b40dac0c6c3d467f8569910f8983 Mon Sep 17 00:00:00 2001
From: Edys Meza <edysmeza@gmail.com>
Date: Fri, 25 Sep 2020 15:10:56 -0600
Subject: [PATCH] Issue 3167034: better handling elementAttributeExists assert
 method

---
 .../Theme/ImageLoadingAttributeTest.php       | 42 ++++++++++++++++---
 1 file changed, 36 insertions(+), 6 deletions(-)

diff --git a/core/modules/system/tests/src/Functional/Theme/ImageLoadingAttributeTest.php b/core/modules/system/tests/src/Functional/Theme/ImageLoadingAttributeTest.php
index 8e30450611f..f2f1f107d0b 100644
--- a/core/modules/system/tests/src/Functional/Theme/ImageLoadingAttributeTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ImageLoadingAttributeTest.php
@@ -2,7 +2,9 @@
 
 namespace Drupal\Tests\system\Functional\Theme;
 
+use Behat\Mink\Exception\ElementHtmlException;
 use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\WebAssert;
 
 /**
  * Tests lazy loading for images.
@@ -27,20 +29,48 @@ class ImageLoadingAttributeTest extends BrowserTestBase {
    * Tests that loading attribute is enabled for images.
    */
   public function testImageLoadingAttribute() {
+    $assert = $this->assertSession();
+
     // Get page under test.
     $this->drupalGet('image-lazy-load-test');
 
     // Loading attribute is added when image dimensions has been set.
-    $this->assertSession()->elementAttributeExists('css', '#with-dimensions img', 'loading');
-    $this->assertSession()->elementAttributeContains('css', '#with-dimensions img', 'loading', 'lazy');
+    $assert->elementAttributeExists('css', '#with-dimensions img', 'loading');
+    $assert->elementAttributeContains('css', '#with-dimensions img', 'loading', 'lazy');
 
     // Loading attribute with lazy default value can be overriden.
-    $this->assertSession()->elementAttributeContains('css', '#override-loading-attribute img', 'loading', 'eager');
+    $assert->elementAttributeContains('css', '#override-loading-attribute img', 'loading', 'eager');
 
     // Without image dimensions loading attribute is not generated.
-    $this->assertSession()->elementAttributeContains('css', '#without-dimensions img', 'alt', 'Image lazy load testing image without dimensions');
-    $this->expectExceptionMessage('The attribute "loading" was not found in the element matching css "#without-dimensions img".');
-    $this->assertSession()->elementAttributeExists('css', '#without-dimensions img', 'loading');
+    $this->assertFalse($this->elementAttributeExists($assert, 'css', '#without-dimensions img', 'loading'));
+  }
+
+  /**
+   * Checks that an attribuet exists in an element.
+   *
+   * Exends Drupal\Tests\WebAssert::elementAttributeExists() method to returns a
+   * boolean type instead throwing an execption when attribuet is not found.
+   *
+   * @param \Drupal\Tests\WebAssert $assert
+   * @param string $selectorType
+   * @param string|array $selector
+   * @param string $attribute
+   *
+   * @see Drupal\Tests\WebAssert::elementAttributeExists()
+   *
+   * @return bool
+   *   Returns TRUE if $attribute exists, FALSE otherwise.
+   */
+  protected function elementAttributeExists(WebAssert $assert, $selectorType, $selector, $attribute) {
+    $attribute_exists = TRUE;
+    try {
+      $assert->elementAttributeExists($selectorType, $selector, $attribute);
+    }
+    catch (ElementHtmlException $th) {
+      $attribute_exists = FALSE;
+    }
+
+    return $attribute_exists;
   }
 
 }