Selenium C# JavaScript exception listening example

JavaScriptExceptions.cs

List<string> exceptionMessages = new List<string>();
IJavaScriptEngine monitor = new JavaScriptEngine(driver);
monitor.JavaScriptExceptionThrown += (sender, e) =>
{
    exceptionMessages.Add(e.Message);
};

await monitor.StartEventMonitoring();

driver.Navigate.GoToUrl("<your site url>");

IWebElement link2click = driver.FindElement(By.LinkText("<your link text>"));
((IJavaScriptExecutor) driver).ExecuteScript("arguments[0].setAttribute(arguments[1], arguments[2]);",
      link2click, "onclick", "throw new Error('Hello, world!')");
link2click.Click();

foreach (string message in exceptionMessages)
{
    Console.WriteLine("JS exception message: {0}", message);
}