Real World Example

A typical retail client project at an IT services company runs two TestNG suites from the same code: a 10-minute smoke suite on every deployment to QA, and a 2-hour regression suite every night.

public class CartTest extends BaseTest {

    @Test(groups = {"smoke", "regression"}, description = "TC_CART_001 add one product")
    public void addOneProduct() {
        open("/products/101");
        click(By.id("add-to-cart"));
        Assert.assertEquals(waitForText(By.id("cart-count"), "1"), "1");
    }

    @Test(groups = "regression", description = "TC_CART_004 remove product updates total")
    public void removeProductUpdatesTotal() {
        SoftAssert soft = new SoftAssert();
        addProducts(101, 205);
        click(By.cssSelector("[data-testid='remove-205']"));
        soft.assertEquals(text(By.id("cart-count")), "1", "count");
        soft.assertEquals(text(By.id("cart-total")), "₹1,299", "total");
        soft.assertAll();
    }
}

mvn test -DsuiteXmlFile=regression.xml -Dbrowser=chrome -Dheadless=true

Total tests run: 312, Passes: 309, Failures: 2, Skips: 1
[ERROR] Tests run: 312, Failures: 2, Errors: 0, Skipped: 1, Time elapsed: 6894 s

TestNG turns scripts into an organised suite: annotations handle setup, assertions decide pass/fail, groups decide what runs when, and reports tell the team what broke.