code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.safari;
  
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  
  import org.junit.jupiter.api.AfterAll;
  import org.junit.jupiter.api.BeforeAll;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.By;
  import org.openqa.selenium.JavascriptExecutor;
  import org.openqa.selenium.StaleElementReferenceException;
  import org.openqa.selenium.WebDriverException;
  import org.openqa.selenium.WebElement;
  import org.openqa.selenium.environment.webserver.AppServer;
  import org.openqa.selenium.environment.webserver.NettyAppServer;
  import org.openqa.selenium.support.ui.ExpectedCondition;
  import org.openqa.selenium.testing.JupiterTestBase;
  import org.openqa.selenium.testing.Pages;
  
  class CrossDomainTest extends JupiterTestBase {
  
    private static AppServer otherServer;
    private static Pages otherPages;
  
    @BeforeAll
    public static void startSecondServer() {
      otherServer = new NettyAppServer();
      otherServer.start();
  
      otherPages = new Pages(otherServer);
    }
  
    @AfterAll
    public static void stopSecondServer() {
      otherServer.stop();
    }
  
    @Test
    void canNavigateBetweenDomains() {
      driver.get(pages.iframePage);
      assertThat(driver.getCurrentUrl()).isEqualTo(pages.iframePage);
      WebElement body1 = driver.findElement(By.tagName("body"));
  
      driver.get(otherPages.iframePage);
      assertThat(driver.getCurrentUrl()).isEqualTo(otherPages.iframePage);
      driver.findElement(By.tagName("body"));
  
      assertThatExceptionOfType(StaleElementReferenceException.class).isThrownBy(body1::getTagName);
    }
  
    @Test
    void canSwitchToAFrameFromAnotherDomain() {
      setupCrossDomainFrameTest();
  
      assertThat(getPageUrl()).isEqualTo(otherPages.iframePage);
      driver.switchTo().defaultContent();
      assertThat(getPageUrl()).isEqualTo(pages.iframePage);
    }
  
    @Test
    void cannotCrossDomainsWithExecuteScript() {
      setupCrossDomainFrameTest();
  
      assertThatExceptionOfType(WebDriverException.class)
          .isThrownBy(
              () ->
                  ((JavascriptExecutor) driver)
                      .executeScript("return window.top.document.body.tagName"));
  
      // Make sure we can recover from the above.
      assertThat(
              ((JavascriptExecutor) driver)
                  .executeScript("return window.document.body.tagName.toLowerCase();"))
          .isEqualTo("body");
    }
  
    private void setupCrossDomainFrameTest() {
      driver.get(pages.iframePage);
  
      WebElement iframe = driver.findElement(By.tagName("iframe"));
      ((JavascriptExecutor) driver)
          .executeScript("arguments[0].src = arguments[1];", iframe, otherPages.iframePage);
  
      assertThat(isTop()).isTrue();
      driver.switchTo().frame(iframe);
      assertThat(isTop()).isFalse();
      wait.until(frameLocationToBe(otherPages.iframePage));
    }
  
    private boolean isTop() {
      return (Boolean) ((JavascriptExecutor) driver).executeScript("return window === window.top");
    }
  
    private String getPageUrl() {
      return (String) ((JavascriptExecutor) driver).executeScript("return window.location.href");
    }
  
    private ExpectedCondition<Boolean> frameLocationToBe(final String url) {
      return ignored -> url.equals(getPageUrl());
    }
  }
  