$this->assertFieldByXPath('//select[@name="settings[custom_block][view_mode]"]/option[@selected="selected"]/@value','test_view_mode','View mode changed to Test View Mode');
// Test the available view mode options.
$this->assertOption('edit-settings-custom-block-view-mode','default','The default view mode is available.');
$this->assertOption('edit-settings-custom-block-view-mode','full','The full view mode is available.');