function JsMessageWhitespaceTest::testMessageClearWithWhitespace

Tests that message.js handles whitespace in empty message wrappers.

This test verifies that getting the message wrapper does not fail when themes have a new line or something in their template.

File

core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageWhitespaceTest.php, line 34

Class

JsMessageWhitespaceTest

Tests that message.js handles whitespace in empty message wrappers.

Namespace

Code

public function testMessageClearWithWhitespace() : void {
  $this->drupalGet('js_message_test_link');
  $this->assertSession()
    ->pageTextContains('JsMessageLinks');
  // Simulate real-world scenario: theme template outputs whitespace
  // in the messages wrapper but no actual message elements.
  $this->getSession()
    ->executeScript("\n      var wrapper = document.querySelector('[data-drupal-messages]');\n      if (wrapper) {\n        // Clear existing content\n        wrapper.innerHTML = '';\n        // Add whitespace like a theme template might (newlines, spaces, tabs)\n        wrapper.innerHTML = '\\n  \\t\\n  \\n';\n      }\n    ");
  // Drupal.Message should work without errors when the wrapper contains only
  // whitespace.
  $this->getSession()
    ->executeScript("\n      try {\n        var msg = new Drupal.Message();\n        msg.add('Test message', {type: 'status'});\n        msg.clear();\n        // Mark success if no errors thrown\n        document.body.setAttribute('data-message-test-success', 'true');\n      } catch (e) {\n        // Mark failure if any errors thrown\n        document.body.setAttribute('data-message-test-error', e.toString());\n      }\n    ");
  // Verify the test completed successfully without JavaScript errors.
  $error = $this->getSession()
    ->evaluateScript("\n      return document.body.getAttribute('data-message-test-error');\n    ");
  $this->assertNull($error);
  // Verify the wrapper still exists after the operations.
  $this->assertSession()
    ->elementExists('css', '[data-drupal-messages]');
}