How to Run Multiple Test Cases in TestNG Suite

TestNG lets you run test methods, classes, and full suites in parallel inside one project. Parallel execution lowers total runtime because threads start the tests concurrently instead of one after another. This guide explains how to run multiple classes (different suites) using TestNG 7.x with Selenium WebDriver.

Step 1) Creating a TestNG.xml file for executing tests

To create the configuration, follow the steps below.

1. Create a new project in Eclipse.
2. Create two packages in the project (name them com.suite1 and com.suite2).
3. Create a class in each package (name them Flipkart.java and Snapdeal.java) and copy the code below into the respective classes.
4. Create a new file in your project and name it testng.xml. Make sure the TestNG plugin is installed (instructions available here). The testng.xml file holds all configuration such as class names, test names, and suite names.

Flipkart.java

package com.suite1;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.Alert;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

public class Flipkart {

    WebDriver driver = new FirefoxDriver();
    String username = ""; // Change to your username and password
    String password = "";

    // This method navigates to the Flipkart URL
    @BeforeClass
    public void init() {
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(60, TimeUnit.SECONDS);
        driver.navigate().to("https://www.flipkart.com");
    }

    // Log in to Flipkart
    @Test
    public void login() {
        driver.findElement(By.partialLinkText("Login")).click();
        driver.findElement(By.cssSelector(".fk-input.login-form-input.user-email")).sendKeys(username);
        driver.findElement(By.cssSelector(".fk-input.login-form-input.user-pwd")).sendKeys(password);
        driver.findElement(By.cssSelector(".submit-btn.login-btn.btn")).click();
    }

    // Search for a product
    @Test
    public void searchAndSelectProduct() {
        driver.findElement(By.id("fk-top-search-box")).sendKeys("moto g3");
        driver.findElement(By.cssSelector("search-bar-submit.fk-font-13.fk-font-bold")).click();
        String css = ".gd-row.browse-grid-row:nth-of-type(1) > div:nth-child(1)>div>div:nth-child(2)>div>a";
        driver.findElement(By.cssSelector(css)).click();
    }

    @Test
    public void buyAndRemoveFromCart() {
        driver.findElement(By.cssSelector(".btn-express-checkout.btn-big.current")).click();
        driver.findElement(By.cssSelector(".remove.fk-inline-block")).click();
        Alert a = driver.switchTo().alert();
        a.accept();
    }

    @Test
    public void logout() {
        Actions s = new Actions(driver);
        WebElement user = driver.findElement(By.partialLinkText(username));
        s.moveToElement(user).build().perform();
        driver.findElement(By.linkText("Logout")).click();
    }

    @AfterClass
    public void quit() {
        driver.close();
    }
}

SnapDeal.java

package com.suite2;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.Alert;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

public class SnapDeal {

    WebDriver driver = new FirefoxDriver();
    String username = ""; // Change to your username and password
    String password = "";
    String pinCode = "";

    // This method navigates to the Snapdeal URL
    @BeforeClass
    public void init() {
        driver.manage().window().maximize();
        driver.manage().timeouts().implicitlyWait(60, TimeUnit.SECONDS);
        driver.navigate().to("https://www.snapdeal.com");
    }

    @Test
    public void login() {
        driver.findElement(By.xpath("//button[text()='Login']")).click();
        driver.switchTo().frame("loginIframe");
        driver.findElement(By.cssSelector("div[onClick='getLoginForm()']")).click();
        driver.findElement(By.id("j_username")).sendKeys(username);
        driver.findElement(By.id("j_password_login")).sendKeys(password);
        driver.findElement(By.id("signin_submit")).click();
        driver.switchTo().defaultContent();
    }

    @Test
    public void searchAndSelectProduct() {
        driver.findElement(By.cssSelector(".col-xs-20.searchformInput.keyword")).sendKeys("iphone 6s");
        driver.findElement(By.cssSelector(".sd-icon.sd-icon-search")).click();
        String css = ".product_grid_row:nth-of-type(1)>div:nth-child(1)";
        driver.findElement(By.cssSelector(css)).click();
    }

    @Test
    public void buyAndRemoveFromCart() {
        driver.findElement(By.xpath("//li[contains(text(),'Silver')]")).click();
        driver.findElement(By.id("pincode-check")).sendKeys(pinCode);
        driver.findElement(By.id("buy-button-id")).click();
        driver.findElement(By.cssSelector("i[title='Delete Item']")).click();
        Alert a = driver.switchTo().alert();
        a.accept();
    }

    @Test
    public void logout() {
        driver.findElement(By.linkText("START SHOPPING NOW")).click();
        Actions s = new Actions(driver);
        WebElement user = driver.findElement(By.cssSelector(".sd-icon.sd-icon-user"));
        s.moveToElement(user).build().perform();
        driver.findElement(By.linkText("Logout")).click();
    }

    @AfterClass
    public void quit() {
        driver.close();
    }
}

TestNG.xml

<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">

<suite thread-count="2" verbose="1" name="Gmail Suite" parallel="tests">

  <test name="flipkart">
    <classes>
      <class name="com.suite1.Flipkart"/>
    </classes>
  </test>

  <test name="Myntra">
    <classes>
      <class name="com.suite2.SnapDeal"/>
    </classes>
  </test>
</suite>

The final project structure looks like the example below.

Step 2) Parallel execution in TestNG

After saving the XML file above, the next step is to run the parallel tests. The code is shown below.

1) thread-count: Defines how many threads TestNG can spin up for parallel execution. A higher value runs more tests at once, up to the CPU limit.

2) verbose: Logs execution details in the console. Allowed values run from 1 to 10. Higher values produce more detailed and granular logs.

3) name: Name of the suite. Here it is “Gmail Suite”.

4) parallel: Tells TestNG what to run concurrently. Valid values are tests, classes, methods, or instances. The default value is none.

Right-click on the testng.xml file and select Run As > TestNG Suite. Once it finishes, you will see the consolidated results.

When you execute the above code, you will get the following output.

Output:

1) Name of the suite defined in testng.xml.

2) Name of the test defined in testng.xml.

3) Name of the class declared in testng.xml.

4) Method names annotated with @Test in the .java file.

The same flow runs for the SnapDeal test, so both classes execute side by side.

Step 3) Running multiple suites from one parent testng.xml

A common requirement on bigger projects is chaining several testng.xml files into a single trigger. TestNG 7.x supports a parent suite that references child suite-file entries, so each child can keep its own thread count, listeners, and parameters. Save each child suite separately, then point the parent to its path. Run only the parent file from Eclipse, Maven, or the command line.

<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Parent Suite" parallel="tests" thread-count="4">
  <suite-files>
    <suite-file path="./flipkart-suite.xml"/>
    <suite-file path="./snapdeal-suite.xml"/>
  </suite-files>
</suite>

This pattern keeps regression, smoke, and sanity suites separate yet reusable. You can also trigger the parent file from Maven Surefire by setting <suiteXmlFile>parent-suite.xml</suiteXmlFile> inside the plugin configuration, which makes the same parallel layout work in continuous integration pipelines.

Step 4) Best practices for parallel TestNG runs

• Pin TestNG 7.x: Use TestNG 7.10 or later with Selenium 4 so W3C-compliant drivers behave consistently across threads.
• Avoid shared state: Move the WebDriver field into a ThreadLocal so each thread holds its own session.
• Tune thread-count: Start with the CPU core count, then watch the emailable HTML report and Grid load before raising it.
• Isolate test data: Use unique users, carts, and pin codes per thread so logins never collide.
• Capture screenshots on failure: Attach them through an ITestListener to debug flaky parallel runs faster.
• Use AI assistance: Tools like Testim, mabl, and CodiumAI can flag flaky tests and suggest stable selectors before the next run.

Conclusion

The example above shows how to use TestNG to execute parallel tests. TestNG 7.x gives you a single XML file to launch multiple test classes, link several child suites, and tune parallel threads, so large Selenium projects finish much faster.

FAQs