Selenium Grid with WebDriver

I had earlier covered in my blog on how to execute your RC cases in selenium grid. But with the commencement of Selenium-2/Webdriver, grid setup has been changed. In the following blog I will cover how to set-up your grid and the changes that will be required for easy execution of cases.


Following things are required:
1. Selenium 2.xx version server jar and Java library. The latest one can be downloaded from the link: Selenium-2
2. Java 1.6 and above
3. TestNg jar . You can download it from the link: TestNG
4. Eclipse with TestNG plugin installed(optional)
5. ChromeDriver. Can be downloaded from: ChromeDriver


The Test Code
Following is an example of test-class that have a test case to search google for "testing" and verifying after clicking it on a link.

import java.net.MalformedURLException;
import java.net.URL;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebDriverBackedSelenium;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Parameters;
import org.testng.annotations.Test;

import com.thoughtworks.selenium.Selenium;

import junit.framework.Assert;

public class Google {
 private Selenium selenium;
 @Parameters({"browser","port"})
 @BeforeClass
 public void beforeClass(String browser,String port){
  DesiredCapabilities capability= new DesiredCapabilities();
  capability.setBrowserName(browser);
  try {
   WebDriver driver= new RemoteWebDriver(new URL("http://localhost:".concat(port).concat("/wd/hub")), capability);
   selenium = new WebDriverBackedSelenium(driver, "http://www.google.com");
  } catch (MalformedURLException e) {
   
   e.printStackTrace();
  }
 }
 
 @Test
 public void search() {
  selenium.open("/");
  selenium.type("id=lst-ib", "testing");
  selenium.click("//input[@value='Google Search']");
  for (int second = 0;; second++) {
   if (second >= 60)
    Assert.fail("timeout");
   try {
    if (selenium
      .isElementPresent("link=Software testing - Wikipedia, the free encyclopedia"))
     break;
   } catch (Exception e) {
   }
   try {
    Thread.sleep(1000);
   } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
  selenium.click("link=Software testing - Wikipedia, the free encyclopedia");
  for (int second = 0;; second++) {
   if (second >= 60)
    Assert.fail("timeout");
   try {
    if (selenium.isTextPresent("Software testing"))
     break;
   } catch (Exception e) {
   }
   try {
    Thread.sleep(1000);
   } catch (InterruptedException e) {

    e.printStackTrace();
   }
  }
 }
 @AfterClass
 public void afterClass(){
  selenium.stop();
 }
 
}

In the above class I am using the TestNG "Parameter" property to provide different data set to the "BeforeClass" method "beforeClass". The beforeClass method accepts two properties "browser" and a "port".

These values are used for initialization of driver and in-turn for initialization of selenium object. In the above code I am using the "WebDriverBackedSelenium" class for creation of the selenium object, so that its easy for guys who had worked on Selenium-1 to understand the code. If you want the code to be purely WebDriver, you can directly use the "driver" object for defining your test-cases.

The main part in this test case is how the driver object is being created:

DesiredCapabilities capability= new DesiredCapabilities();
capability.setBrowserName(browser);
WebDriver driver= new RemoteWebDriver(new URL("http://localhost:".concat(port).concat("/wd/hub")), capability);

The above code creates an object of DesiredCapability and then set the browser value to it. Now using this "capability" object I am creating the webdriver object using the "RemoteWebDriver" class. This tells the selenium on which browser the test-case needs to run and where the server is located. In this example I am assuming the server to be running locally. In case it is on different system the "localhost" needs to be re-placed with the ip of the said system.

TestNG configuration

For parallel execution you need to use the TestNG configuration. Following is an "testng.xml" file for the above said test class. The said configuration executes the test-cases across different browser.

<suite name="Selenium TestNG Suite" parallel="tests"
    thread-count="5">

    <test name="Selenium TestNG - 1">
        <parameter name="browser" value="firefox" />
        <parameter name="port" value="4444" />
        <classes>
            <class name="com.test.testng.Google" />
        </classes>
    </test>
    <test name="Selenium TestNG - 2">
        <parameter name="browser" value="chrome" />
        <parameter name="port" value="4444" />
        <classes>
            <class name="com.test.testng.Google" />
        </classes>
    </test>

</suite>

In the above configuration, I am configuring TestNG to run "tests" in parallel. Also there are two different tests inside a suite. For each test a different "browser" parameter value has been configured.

Selenium-Grid server

Now start your grid using the following commands. Run each command in a seperate terminal or command prompt by going to the directory containing your selenium-server-standalone-2.x.x.jar. In the following example I am using the 2.7.0 version of selenium.

For Hub:

java -jar selenium-server-standalone-2.7.0.jar -role hub

For a firefox based node:

java -jar selenium-server-standalone-2.7.0.jar -role webdriver -hub http://localhost:4444/grid/register -port 5556 -browser browserName=firefox

For google-chrome based node:

java -Dwebdriver.chrome.driver=/path/to/chromedriver -jar selenium-server-standalone-2.7.0.jar -role webdriver -hub http://localhost:4444/grid/register -port 5555 -browser browserName=chrome

Before running  the above command  you need to provide the chrome-driver path to the property "-Dwebdriver.chrome.driver".

Now run your testng.xml from eclipse by selecting it -> Right click -> Run as -> TestNG suite(this will work only if you have TestNG plugin installed in your eclipse.)

Or you can choose other ways to execute "testng.xml" like from command prompt, using ant or maven.

Once you run the above testng.xml. TestNG will execute the cases from the Google class on grid across different browsers firefox and google-chrome as configured.

You can do configurations for environment like OS (Linux,Windows), browser, browser-version and all and then you can run you cases on particular type of environment by configuring them accordingly. More details can be found at the following URL:
http://code.google.com/p/selenium/wiki/Grid2

Data-Driven testing using Junit and TestNG

Most of the guys who are into automation may be knowing the term Data-Driven testing. But the word will still be new for some fresh faces in the field of automation. In this blog I will explain what is Data-Driven testing and will give an example of Data-driven testing using Junit and TestNG frameworks.

Data-Driven testing as the name suggests is a test driven by the Data. For ex. You have a user detail form where you need to enter details of multiple users and save them. Here if you have 5 different user data available and you have to write automation cases for these, you may end up writing 5 different automation test cases(one for each user data).

If you apply a Data-Driven approach you will end up with only one test-case, that is filling the form with user data and then submitting it. The test case will get executed based on the data provided to it. In this case it will be 5 and hence the test case will get executed 5 times with different data-set.

The advantage of using a Data-driven approach is that you reduce your effort in writing/maintaing test-cases for your different type of data. In case of additions or deletion of new/old entries , you just have to change the data and not your actual test-case.

Following I will mention a Data-Driven approach for searching on google with different data using Junit and TestNg frameworks:


Using Junit:

import static org.junit.Assert.fail;

import com.thoughtworks.selenium.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebDriverBackedSelenium;
import org.openqa.selenium.firefox.FirefoxDriver;

import java.util.Arrays;
import java.util.List;

@RunWith(Parameterized.class)
public class JunitGoogleBase {
  public Selenium selenium;
  WebDriver driver;
  private String testData;
  
  public JunitGoogleBase(String testData){
   this.testData=testData;
  }
  
  @Parameters
   public static List< Object[]> data() {
    return Arrays.asList(new Object[][]{{"testing"},{"Software testing"}});
   }

  @Before
  public void setUp() throws Exception {
   driver= new FirefoxDriver();
   selenium = new WebDriverBackedSelenium(driver, "http://www.google.com"); 
   selenium.open("http://www.google.com");
  }

  @Test
  public void testSearch() throws Exception {
   selenium.open("/");
   selenium.type("id=lst-ib", testData);
   selenium.click("//input[@value='Google Search']");
   for (int second = 0;; second++) {
    if (second >= 60) fail("timeout");
    try { if (selenium.isElementPresent("link=Software testing - Wikipedia, the free encyclopedia")) break; } catch (Exception e) {}
    Thread.sleep(1000);
   }
   selenium.click("link=Software testing - Wikipedia, the free encyclopedia");
   for (int second = 0;; second++) {
    if (second >= 60) fail("timeout");
    try { if (selenium.isTextPresent("Software testing")) break; } catch (Exception e) {}
    Thread.sleep(1000);
   }
   
  }

  @After
  public void tearDown() throws Exception {
   selenium.stop();
   
  }
}

Using TestNg:

import com.thoughtworks.selenium.*;


import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebDriverBackedSelenium;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.Assert;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;



public class TestNGGoogleBase {
  public Selenium selenium;
  WebDriver driver;
  
  @DataProvider(name="parameter")
   public static Object[][] data() {
    return new Object[][]{{"testing"},{"Software testing"}};
   }

  @BeforeMethod
  public void setUp() throws Exception {
   driver= new FirefoxDriver();
   selenium = new WebDriverBackedSelenium(driver, "http://www.google.com"); 
   selenium.open("http://www.google.com");
  }

  @Test(dataProvider="parameter")
  public void testSearch(String testData) throws Exception {
   selenium.open("/");
   selenium.type("id=lst-ib", testData);
   selenium.click("//input[@value='Google Search']");
   for (int second = 0;; second++) {
    if (second >= 60) Assert.fail("timeout");
    try { if (selenium.isElementPresent("link=Software testing - Wikipedia, the free encyclopedia")) break; } catch (Exception e) {}
    Thread.sleep(1000);
   }
   selenium.click("link=Software testing - Wikipedia, the free encyclopedia");
   for (int second = 0;; second++) {
    if (second >= 60) Assert.fail("timeout");
    try { if (selenium.isTextPresent("Software testing")) break; } catch (Exception e) {}
    Thread.sleep(1000);
   }
  }

  @AfterMethod
  public void tearDown() throws Exception {
   selenium.stop();
  }
 

}

The main difference in the above two functions is that you provide a Paramaterized option to the class in Junit and supply data to the constructor of the said class. Where as in TestNG you do the same at the test-method level.

Its simple to do data-driven testing in TestNG framework as you can provide a different data providing function for each test-method, but the same is not possible in Junit.

Running tests on Google Chrome using Webdriver

While automating your web-application using webdriver, many may have faced problems in executing your cases on Google-chrome. Whenever you try to use webdriver object for executing your cases on chrome using the following code:

DesiredCapabilities capability = DesiredCapabilities.chrome();

you most probably get the following error:

The path to the chromedriver executable must be set by the webdriver.chrome.driver system property; for more information, see http://code.google.com/p/selenium/wiki/ChromeDriver. The latest version can be downloaded from http://code.google.com/p/chromium/downloads/list

The solution to this error that has been mentioned in the given URL  "http://code.google.com/p/selenium/wiki/ChromeDriver" is  to set the chromedriver path to the variable "webdriver.chrome.driver". But how exactly to set the path and use it for your test execution is not given there. So I though to just document it here on my blog.

For setting the  "webdriver.chrome.driver" value and for using google-chrome to execute your automated tests, you can use one of the following methods:

Method - 1:
Start the selenium server using the following command:

java -Dwebdriver.chrome.driver=/path/to/chromedriver  -jar selenium-server-standalone-2.7.0.jar

And in your Java code you use the chrome driver in the following way:

 DesiredCapabilities capability = DesiredCapabilities.chrome();
WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), capability);

The advantage of using this method is that you can execute your test-cases in a remote machine and this is advantageous when you want to run it on grid.


Method - 2:
Set the system property  "webdriver.chrome.driver" using System.setProperty()  in your code and then try to execute your cases on Chrome.

System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");
WebDriver driver = new ChromeDriver();

This method works well when your tests are getting execute on a local machine and you are not starting any selenium server.

Following are some important links for Chrome driver:
Webdriver Chromedriver page:
http://code.google.com/p/selenium/wiki/ChromeDriver


ChromeDriver download page for downloading the ChromeDriver server:
http://code.google.com/p/chromium/downloads/list