Question

Below I’m debugging and throwing an exception on purpose to find out the value of a JavaScript call from WebDriver. How can I cast the jQuery call so I can print a string (based on the number of tr tags in my table with id of “viewtable”) in my exception message? I imagine this has absolutely nothing to do with the C# code. I bet the driver can’t execute the jQuery call properly, but I don’t know the correct syntax.

Exception thrown by NUnit:

Selenium.ProductPricing.TheUntitledTest:
System.InvalidCastException : Unable to cast object of type 'System.Int64' to type 'System.String'.

Environment:

• Class Library project is called Selenium.sln/Selenium.csproj
• project referencing NUnit dll & Selenium C# client drivers including WebDriver dll files
• project has one class class called ProductPricing.cs
• running class library dll in NUnit 2.6

Test Case C# code:
(search for “BAD!” below)

using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Support.UI;
using OpenQA.Selenium.Firefox;
using OpenQA.Selenium.IE;
using OpenQA.Selenium.Chrome;
using Selenium;
using System.Text;
using System;

namespace Selenium
{
    [TestFixture]
    public class ProductPricing
    {
        private IWebDriver driver;
        private StringBuilder verificationErrors;
        private string baseURL;

        [SetUp]
        public void Setup()
        {
            driver = new FirefoxDriver();
            baseURL = "http://buyemp.qa.xxx.com/";

            ISelenium selenium = new WebDriverBackedSelenium(driver, baseURL);
            selenium.Start();

            verificationErrors = new StringBuilder();
        }

        [TearDown]
        public void TeardownTest()
        {
            try
            {
                driver.Quit();
            }
            catch (Exception)
            {
                // Ignore errors if unable to close the browser
            }
            Assert.AreEqual("", verificationErrors.ToString());
        }

        [Test]
        public void TheUntitledTest()
        {
            //String var_skip_product = "false";
            String var_admin_user = "[e-mail]";
            String var_admin_pass = "notsure";
            driver.Navigate().GoToUrl(baseURL + "/admin");
            driver.FindElement(By.Id("email")).Clear();
            driver.FindElement(By.Id("email")).SendKeys(var_admin_user);
            driver.FindElement(By.Id("password")).Clear(); 
            driver.FindElement(By.Id("password")).SendKeys(var_admin_pass);
            driver.FindElement(By.CssSelector("input[type=\"submit\"]")).Click();            
            driver.WaitForElement(By.LinkText("Products"));
            driver.FindElement(By.LinkText("Products")).Click();
            String var_product_row = "24";  // force script to start on row 24/25

            //// ERROR: Caught exception [unknown command [getTableTrCount]]
            // Command: getTableTrCount | Target: viewtable | Value: var_table_row_count (user extensions don't work in WebDriver)
            IJavaScriptExecutor js = driver as IJavaScriptExecutor;

            // this one throws an exception with value 22 - GOOD!
            //int x = Convert.ToInt32((string)js.ExecuteScript("return '22'"));

            // this one throws an exception with the cast exception - BAD!
            int x = Convert.ToInt32((string)js.ExecuteScript("return $('#viewtable tr').length"));

            // explicitly throwing Selenium exception so we can debug this code in NUnit
            throw new SeleniumException(x.ToString());

            // Command: storeText | Target: //a[@title='last page']/text() | Value: var_page_total_text
            // Conversion: String var_page_total_text = driver.FindElement(By.XPath("//a[@title='last page']/text()")).Text;
            String var_page_total_text = driver.FindElement(By.XPath("//a[@title='last page']")).Text;

            //// ERROR: Caught exception [ERROR: Unsupported command [getEval]]
            // Command: eval | Target: javascript{storedVars['var_page_total_text'].substring(1,storedVars['var_page_total_text'].length-1)}
            //int var_page_total = Convert.ToInt32(var_page_total_text.Substring(1,var_page_total_text.Length-1));           

        }    

        private bool IsElementPresent(By by)
        {
            try
            {
                driver.FindElement(by);
                return true;
            }
            catch (NoSuchElementException)
            {
                return false;
            }
        }
    }
}

Answer 1

Just from the exception I’m assuming that ExecuteScript is returning an int64 for $("query").length and a string for $("query").html().

So you might want to try this:

string x = js.ExecuteScript("return $('#viewtable tr').length").ToString();

or if you prefer a number:

long x = (long)js.ExecuteScript("return $('#viewtable tr').length");

Not sure about the second one but the first one should work.