Parameterization in TestNG and TestNG DataProviders

TestNG Parameters

There are times when we would like to run our tests against different data sets. Instead of hard coding the data set within tests itself, it will be more appropriate if we could pass our data as parameters to the test method. Thus the test logic remains same but the data on which the test is run changes and this is called data-driven testing.
One of the most important features of TestNG is its data-driven testing. It allows the user to pass parameter values to the test method as arguments, so the test ends up running for each data-set passed in.
TestNG supports two different ways of injecting parameter values.

1. Parameterization through testng.xml
2. DataProvider

In most cases, you'll come across a scenario where the business logic requires a hugely varying number of tests. Parameterized tests allow developers to run the same test over and over again using different values.

Passing Parameters with testng.xml 
With this technique, you define the simple parameters in the testng.xml file and then reference those parameters in the source files. Let us have an example to demonstrate how to use this technique to pass parameters.

I am going to create new TestNG class 'ParametrizationTest', Open Amazon site and try logging in by passing username and password as parameters.

Add the annotation @Parameters("myName") to this method. The parameter would be passed a value from testng.xml

package automationFramework;
import org.testng.annotations.Parameters;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.safari.SafariDriver;
import org.testng.Assert;
import org.testng.annotations.Test;

public class ParametrizationTest {
    public static WebDriver sDriver = new SafariDriver();
  @Test
  @Parameters({"sUsername","sPassword"})
  public void testOne(String sUsername, String sPassword) throws InterruptedException {
      sDriver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
      //Open website
      sDriver.get("http://amazon.com");
      //Verify Page title
      WebElement myAccountLink = sDriver.findElement(By.id("nav-link-yourAccount"));
     
      //Adding assertion check here. Test will only continue if below statement is True.
      Assert.assertTrue(myAccountLink.isDisplayed());
      //My Account Link will be clicked only if the above condition is true
      myAccountLink.click();
     
      Thread.sleep(1000);
      sDriver.findElement(By.xpath(".//*[@id='ap_email']")).sendKeys(sUsername);
      sDriver.findElement(By.xpath(".//*[@id='ap_password']")).sendKeys(sPassword);
      sDriver.findElement(By.xpath(".//*[@id='signInSubmit']")).click();
     
  }
}

Next, Pass the Parameters in testng.xml and run it. The output will look like this-


 

TestNG DataProviders

Passing Parameters with Dataproviders

When you need to pass complex parameters or parameters that need to be created from Java (complex objects, objects read from a property file or a database, etc.), parameters can be passed using Data providers. A Data Provider is a method annotated with @DataProvider. This annotation has only one string attribute: its name. If the name is not supplied, the data provider’s name automatically defaults to the method’s name. A data provider returns an array of objects.
The following examples demonstrate how to use data providers.

 Let's start by creating a new TestNG class 'DataProviderTest'

1)  Define the method logons() which is defined as a Dataprovider using the annotation. This method returns array of object array.

2) Add a method test() to your DataProviderTest class. This method takes two strings as input parameters.

3) Add the annotation @Test(dataProvider = “LoginValidation”) to this method. The attribute dataProvider is mapped to “LoginValidation”.

package automationFramework;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.safari.SafariDriver;
import org.testng.Assert;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

public class DataProviderTest {
    public static WebDriver sDriver = new SafariDriver();
   
  @DataProvider(name= "LoginValidation")
  public static Object[][] credentials() {
 return new Object[][] { { "user1", "pass1" }, { "user2", "pass2" }};

}
  @Test(dataProvider="LoginValidation")
  public void testOne(String sUsername,String sPassword ) throws InterruptedException {
      sDriver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
      //Open website
      sDriver.get("http://amazon.com");
      //Verify Page title
      WebElement myAccountLink = sDriver.findElement(By.id("nav-link-yourAccount"));
     
      //Adding assertion check here. Test will only continue if below statement is True.
      Assert.assertTrue(myAccountLink.isDisplayed());
      //My Account Link will be clicked only if the above condition is true
      myAccountLink.click();
     
      Thread.sleep(1000);
      sDriver.findElement(By.xpath(".//*[@id='ap_email']")).sendKeys(sUsername);
      sDriver.findElement(By.xpath(".//*[@id='ap_password']")).sendKeys(sPassword);
      sDriver.findElement(By.xpath(".//*[@id='signInSubmit']")).click(); 
  }
}
 
Run testng.xml file and see the Test Result. The output will look like this and it will show all the parameters -