drupalCreateUser([ 'administer block classes', 'administer blocks', ]); $this->drupalLogin($admin_user); // Add a content block with custom CSS class. $this->drupalGet('admin/structure/block/add/system_main_block/classy', ['query' => ['region' => 'content']]); $edit = [ 'region' => 'content', 'third_party_settings[block_class][classes]' => 'TestClass_content', ]; $this->drupalPostForm(NULL, $edit, $this->t('Save block')); // Add a user account menu with a custom CSS class. $this->drupalGet('admin/structure/block/add/system_menu_block:account/classy', ['query' => ['region' => 'content']]); $edit = [ 'region' => 'secondary_menu', 'third_party_settings[block_class][classes]' => 'TestClass_menu', ]; $this->drupalPostForm(NULL, $edit, $this->t('Save block')); // Go to the front page of the user. $this->drupalGet(''); // Assert the custom class in the content block. $this->assertRaw('

'); // Assert the custom class in user menu. $this->assertRaw('