Selenium“NoSuchAlertError：没有打开警报”错误答案

【问题标题】：Selenium "NoSuchAlertError: no alert open" errorSelenium“NoSuchAlertError：没有打开警报”错误
【发布时间】：2014-06-25 01:06:36
【问题描述】：

在 Selenium 中，我单击一个按钮并出现一个警告框，我尝试接受该警告框，但它给了我一个错误。

          element.click();
          driver.switchTo().alert().accept();

非常不一致...有时测试通过，有时它给我错误...

错误看起来像：

NoSuchAlertError: no alert open
  (Session info: chrome=34.0.1847.131)
  (Driver info: chromedriver=2.9.248307,platform=Mac OS X 10.9.2 x86_64)
      at new bot.Error (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/atoms/error.js:109:18)
      at Object.bot.response.checkResponse (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/atoms/response.js:106:9)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/webdriver.js:276:20
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1465:10
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:678:49
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/http/http.js:96:5
      at IncomingMessage.<anonymous> (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/http/index.js:114:7)
      at IncomingMessage.EventEmitter.emit (events.js:117:20)
      at _stream_readable.js:920:16
      at process._tickCallback (node.js:415:13)
  ==== async task ====
  WebDriver.switchTo().alert()
      at webdriver.WebDriver.schedule (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/webdriver.js:267:15)
      at webdriver.WebDriver.TargetLocator.alert (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/webdriver.js:1429:27)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/test/bandbooking/form.js:87:39
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at then (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:478:7)
      at Object.webdriver.promise.asap (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:723:11)
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1609:25)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at then (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:478:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:369:18)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at then (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:478:7)
      at Object.webdriver.promise.asap (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:723:11)
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1609:25)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at then (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:478:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:369:18)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1465:10
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at then (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:478:7)
      at Object.webdriver.promise.asap (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:723:11)
      at newFrame.then.e (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1614:25)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at webdriver.promise.ControlFlow.resolveFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1519:9)
      at webdriver.promise.ControlFlow.getNextTask_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1488:12)
      at webdriver.promise.ControlFlow.runEventLoop_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1446:59)
      at wrapper [as _onTimeout] (timers.js:252:14)
      at Timer.listOnTimeout [as ontimeout] (timers.js:110:15)
  ==== async task ====
      at Context.<anonymous> (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/testing/index.js:126:14)
      at Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:196:15)
      at Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:452:12
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:309:7
      at next (/usr/local/lib/node_modules/mocha/lib/runner.js:247:23)
      at /usr/local/lib/node_modules/mocha/lib/runner.js:271:7
      at done (/usr/local/lib/node_modules/mocha/lib/runnable.js:185:5)
      at /usr/local/lib/node_modules/mocha/lib/runnable.js:199:9
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/testing/index.js:92:5
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1465:10
      at Object.webdriver.promise.asap (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:732:5)
      at newFrame.then.e (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1614:25)
      at /Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/goog/base.js:1178:15
      at webdriver.promise.ControlFlow.runInNewFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1598:20)
      at notify (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:428:12)
      at notifyAll (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:397:7)
      at resolve (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:375:7)
      at fulfill (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:493:5)
      at webdriver.promise.ControlFlow.resolveFrame_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1519:9)
      at webdriver.promise.ControlFlow.getNextTask_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1488:12)
      at webdriver.promise.ControlFlow.runEventLoop_ (/Users/kstrife/Desktop/experiments/seleniumNode/selenium-webdriver/lib/webdriver/promise.js:1446:59)
      at wrapper [as _onTimeout] (timers.js:252:14)
      at Timer.listOnTimeout [as ontimeout] (timers.js:110:15)

【问题讨论】：

标签： javascript node.js selenium selenium-webdriver selenium-chromedriver

【解决方案1】：

我只是睡了 1 秒才接受。

element.click();
driver.sleep(1000);
driver.switchTo().alert().accept();

【讨论】：

【解决方案2】：

你不妨改成：

element.click();
while (true)
{
    try
    {
        driver.switchTo().alert().accept();
        break;
    }
    catch (NoSuchAlertError error)
    {
        Thread.sleep(100);
    }
}

这将：

请注意安全，以防弹出窗口出现的时间超过 1000 毫秒。
提高性能，因为显示弹出窗口的平均时间可能不到 1000 毫秒。

如果您正在运行单线程应用程序，那么您不妨完全摆脱Thread.sleep，因为将系统中唯一的线程置于睡眠状态并没有任何好处。除此之外，您可能还需要考虑在尝试一定次数后放弃并退出循环。

【讨论】：

如果警报从不显示，那将是一个无限循环！应该通过超时增强。

【解决方案3】：

我总是尽量避免Thread.sleep() 和不必要的 throw-catch 异常。
以下解决方案将实现两者，您可以根据需要更改计数值。如果没有弹出窗口也不会导致无限循环。

int count = 0;
do{
   if (driver.getWindowHandles().size() > 1) {
     // Alert is present
     driver.switchTo().alert().accept();
     break;
   }
} while(count < 100);

【讨论】：

【解决方案4】：

您可以使用显式等待警报来代替Thread.sleep，如下所示：

WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element = wait.until(ExpectedConditions.alertIsPresent());

然后接受警报：

driver.switchTo().alert().accept();

【讨论】：

对于那些使用 webdriver / node.js - 试试 driver.wait(webdriver.until.alertIsPresent())
不适合我使用.alertIsPresent() 在这里问stackoverflow.com/q/44650624/248616

【解决方案5】：

documented solution 不起作用。

// this is the documented solution, which doesn't work
driver.switchTo().alert().dismiss().then(null, function(e) {
  if (e.code !== webdriver.ErrorCode.NO_SUCH_ALERT) {
    throw e;
  }
});

无论如何它只会抛出NoSuchAlertError: no alert open。然而，这种修改后的方法有效：

driver.switchTo().alert().thenCatch(function (e) {
    // 27 maps to bot.ErrorCode.NO_MODAL_DIALOG_OPEN: http://selenium.googlecode.com/git/docs/api/javascript/source/lib/atoms/error.js.src.html#l31
    if (e.code !== 27) { throw e; }
})
.then(function (alert) {
    if (alert) { return alert.dismiss(); }
});

这会尝试切换到打开的警报。
如果未找到警报，则处理 NoSuchAlertError 异常，但抛出其他错误（因为我们不想吞噬所有错误）。
李>
如果找到，则调用dismiss 将其关闭。如果需要，请随时致电accept。

注意：thenCatch的位置很关键。这是违反推理和他们记录在案的控制流程的，但这就是今天的工作方式。

【讨论】：

这不适用于量角器。我将驱动程序替换为 protractor.getInstance() 没有帮助。你知道怎么做吗
对不起，不知道量角器。