Refactored for simplicity.

tests/src/FunctionalJavascript/ModalHeightTest.php

@@ -5,14 +5,12 @@ namespace Drupal\Tests\layout_paragraphs\FunctionalJavascript;
 /**
  * Tests that buttons remain reachable even with tall modal heights.
  *
- * @requires module layout_paragraphs_alter_controls_test
- *
  * @group layout_paragraphs
  */
 class ModalHeightTest extends BuilderTestBase {
 
   /**
-   * Tests modal height.
+   * Tests that buttons remain reachable even with tall modal heights.
    */
   public function testModalHeight() {
     $this->loginWithPermissions([
@@ -26,15 +24,18 @@ class ModalHeightTest extends BuilderTestBase {
     $page->find('css', '.lpb-btn--add')->click();
     $this->assertSession()->assertWaitOnAjaxRequest(1000, 'Unable to click add a component.');
 
-    // Add a text component.
+    // Open the "Create text" dialog.
     $page->clickLink('text');
-    $this->assertSession()->assertWaitOnAjaxRequest(1000, 'Unable to select text component.');
+    $this->assertSession()->waitForText('Create text');
 
     // Force the dialog height to expand beyond the viewport.
+    // Since the dialog height is 'auto' by default, increasing the height of
+    // the dialog's content will automatically increase the dialog's height.
     $this->getSession()->executeScript('jQuery(\'.layout-paragraphs-component-form\').height(\'2000px\');');
+    // Pause for UI to update.
+    $this->getSession()->wait(1000);
 
-    // Save button should be reachable.
-    $this->assertSession()->waitForElementVisible('css', '.ui-dialog-buttonpane .lpb-btn--save', 1000);
+    // Save button should still be reachable.
     $this->assertSession()->assertVisibleInViewport('css', '.ui-dialog-buttonpane .lpb-btn--save');
 
   }