Using TestNG for parallel execution on Selenium Grid

Following I will mention how to integrate TestNG with Selenium-Grid code and use it for parallel execution of test cases.
For this you create a Base class where you define the following two functions.


protected void startSession(String seleniumHost, int seleniumPort, String browser, String webSite)
throws Exception {

startSeleniumSession(seleniumHost, seleniumPort, browser, webSite);
session().setTimeout(TIMEOUT);

}

protected void closeSession() throws Exception {

closeSeleniumSession();

}

The above two functions are for the starting and closing the session in Selenium Grid. The references of it can be found in my earlier posts.

Now import the testng annotation class “org.testng.annotations.*” onto the Base Class.

Add @BeforeClass before the “startSession” method and @AfterClass before the “closeSession” method.

Now write your test cases in a way that all dependent test cases are in one class.

So whenever you execute the testNG it will call the “startSession” and “closeSession” before and after each test class execution. The “startSession” will create a Selenium session for test execution and return it to the test class. Where as the “closeSession” will close the session.

For parallel execution define inside the testng.xml file the attributes “suite” tag as “parallel="classes" thread-count="2" ”.
This will tell TestNG that parallel execution needs to be done for classes and max. Thread count for it is “2”.

Define 2 different test classes both extending the Base Class which defines the “startSession” and “closeSession” methods. Start a Selenium Grid Hub and register two Selenium remote control to the Hub. Now try running the package containing these classes using the TestNG.

You will see 2 different tests running in parallel in Selenium Grid each for Selenium Remote Control registered to the Hub.
The “startSeleniumSession” inside the “startSession” method create a unique selenium session for each of the test class and use that session for test class execution. Creating a session,registering the session with a Remote control and maintaining the session is done by Selenium Grid where as using TestNG framework we define how many sessions we need to create and how the test execution should be. So using the features of both TestNG and Selenium Grid we achieve Parallel execution of our automation testcases.

Currently here I had suggested to use @Before/AfterClass annotations in Base Class. You can use any of the other available @Before/After annotations available in TestNG depending upon your tests.