network.cs

public async Task TestNetworkInterceptor(IWebDriver driver)
{
    NetworkRequestHandler handler = new NetworkRequestHandler()
    {
        RequestMatcher = (request) =>
        {
            return request.Url.Contains("the-internet.herokuapp.com");
        },
        ResponseSupplier = (request) =>
        {
            var response = new HttpResponseData();
            response.StatusCode = 200;
            foreach (var header in request.Headers)
            {
                response.Headers.Add(header.Key, header.Value);
            }
            response.Body = "<p>Intercepted from The Internet</p>";
            return response;
        }
    };

    INetwork interceptor = driver.Manage().Network;
    await interceptor.StartMonitoring();

    driver.Url = "http://the-internet.herokuapp.com/";
    string bodyText = driver.FindElement(By.CssSelector("h1")).Text;
    if (bodyText.Contains("Welcome to the-internet"))
    {
        Console.WriteLine("Interception without handler PASSED");
    }
    else
    {
        Console.WriteLine("Interception without handler FAILED");
    }

    interceptor.AddRequestHandler(handler);
    driver.Url = "http://the-internet.herokuapp.com/checkboxes";
    string text = driver.FindElement(By.CssSelector("p")).Text;
    if (text == "Intercepted from The Internet")
    {
        Console.WriteLine("Interception with handler PASSED");
    }
    else
    {
        Console.WriteLine("Interception with handler FAILED");
    }

    await interceptor.StopMonitoring();
}