Fix failing test in diff.feature

Author: smulvih2

modules/custom/wxt_core/tests/context/CkEditorContext.behat.inc

@@ -184,4 +184,28 @@ final class CkEditorContext extends DrupalSubContextBase {
     return explode(',', $keys);
   }
 
+  /**
+   * Switches CKEditor 5 to source editing mode.
+   *
+   * @throws \Behat\Mink\Exception\ExpectationException
+   *   Thrown when the source editing button cannot be found.
+   *
+   * @When I switch CKEditor to source mode
+   */
+  public function switchCkeditorToSourceMode() {
+    $selector = 'button.ck-source-editing-button';
+    $this->getSession()->wait(10000, "document.querySelector('$selector') !== null");
+
+    $element = $this->getSession()->getPage()->find('css', $selector);
+
+    if (!$element) {
+      throw new ExpectationException(
+        'Could not find the CKEditor source editing button.',
+        $this->getSession()->getDriver()
+      );
+    }
+
+    $element->click();
+  }
+
 }

tests/features/workflow/diff.feature

@@ -9,7 +9,7 @@ Feature: Diffing different revisions of content
     When I visit "/drupal-10"
     And I follow "Edit"
     # CKEditor5 hides the textarea; switch to Source mode so body[0][value] is editable.
-    And I click "button.ck-source-editing-button" element
+    And I switch CKEditor to source mode
     And I enter "Second revision" for "body[0][value]"
     And I press "Save"
     And I follow "Edit"