function ThemeTest::testAttributeMerging
Tests attribute merging.
Render arrays that use a render element and templates (and hence call template_preprocess()) must ensure the attributes at different occasions are all merged correctly:
- $variables['attributes'] as passed in to the theme hook implementation.
- the render element's #attributes
- any attributes set in the template's preprocessing function
File
- 
              core/modules/ system/ tests/ src/ Kernel/ Theme/ ThemeTest.php, line 39 
Class
- ThemeTest
- Tests low-level theme functions.
Namespace
Drupal\Tests\system\Kernel\ThemeCode
public function testAttributeMerging() {
  $theme_test_render_element = [
    'elements' => [
      '#attributes' => [
        'data-foo' => 'bar',
      ],
    ],
    'attributes' => [
      'id' => 'bazinga',
    ],
  ];
  $this->assertThemeOutput('theme_test_render_element', $theme_test_render_element, '<div id="bazinga" data-foo="bar" data-variables-are-preprocessed></div>' . "\n");
}Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.
