class JavascriptGetDrupalSettingsTest

class JavascriptGetDrupalSettingsTest extends WebDriverTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'test_page_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * Tests retrieval of Drupal settings.
     *
     * @see \Drupal\FunctionalJavascriptTests\WebDriverTestBase::getDrupalSettings()
     */
    public function testGetDrupalSettings() {
        $this->drupalLogin($this->drupalCreateUser());
        $this->drupalGet('test-page');
        // Check that we can read the JS settings.
        $js_settings = $this->getDrupalSettings();
        $this->assertSame('azAZ09();.,\\\\/-_{}', $js_settings['test-setting']);
        // Dynamically change the setting using JavaScript.
        $script = <<<EndOfScript
(function () {
  drupalSettings['test-setting'] = 'foo';
})();
EndOfScript;
        $this->getSession()
            ->evaluateScript($script);
        // Check that the setting has been changed.
        $js_settings = $this->getDrupalSettings();
        $this->assertSame('foo', $js_settings['test-setting']);
    }

}