Why TestNG structures test execution in Selenium Java - Automation Benefits in Action

Verify TestNG test execution order with multiple test methods

Preconditions (2)

Step 1: Create a TestNG test class with three test methods: testA, testB, testC

Step 2: Annotate test methods with @Test and assign priorities: testA(priority=2), testB(priority=1), testC(priority=3)

Step 3: In each test method, open the browser and navigate to https://example.com

Step 4: Print a message to the console indicating which test method is running

Step 5: Run the TestNG test suite

Step 6: Observe the order in which test methods execute

✅ Expected Result: Test methods execute in the order of their priority: testB, testA, testC. Console output shows messages in this order.

Automation Requirements - TestNG with Selenium WebDriver

Assertions Needed:

Verify that test methods run in the order of their assigned priority

Verify that the browser navigates to the correct URL in each test

Best Practices:

Use @BeforeMethod and @AfterMethod for setup and teardown

Use explicit waits if needed

Use meaningful test method names

Avoid hardcoded waits

Use assertions to verify expected conditions

Automated Solution

Selenium Java

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.Assert;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class TestNGExecutionOrder {
    private WebDriver driver;
    private final String url = "https://example.com";

    @BeforeMethod
    public void setUp() {
        // Set path to chromedriver executable if needed
        driver = new ChromeDriver();
    }

    @AfterMethod
    public void tearDown() {
        if (driver != null) {
            driver.quit();
        }
    }

    @Test(priority = 2)
    public void testA() {
        driver.get(url);
        System.out.println("Running testA");
        Assert.assertEquals(driver.getCurrentUrl(), url, "URL should be https://example.com");
    }

    @Test(priority = 1)
    public void testB() {
        driver.get(url);
        System.out.println("Running testB");
        Assert.assertEquals(driver.getCurrentUrl(), url, "URL should be https://example.com");
    }

    @Test(priority = 3)
    public void testC() {
        driver.get(url);
        System.out.println("Running testC");
        Assert.assertEquals(driver.getCurrentUrl(), url, "URL should be https://example.com");
    }
}

This test class uses TestNG to demonstrate how test execution order is controlled by the priority attribute.

The @BeforeMethod sets up the browser before each test, and @AfterMethod closes it after each test to keep tests independent.

Each test method navigates to the same URL and prints a message to the console to show execution order.

Assertions check that the browser is on the expected URL.

When running this test, TestNG runs testB first because it has priority 1, then testA (priority 2), then testC (priority 3).

This shows how TestNG structures test execution order based on priority, helping organize tests clearly and predictably.

Common Mistakes - 4 Pitfalls

Not using @BeforeMethod and @AfterMethod for setup and teardown

Not assigning priorities and expecting tests to run in code order

Using Thread.sleep instead of proper waits

Hardcoding URLs or test data inside test methods

Bonus Challenge

Now add data-driven testing with 3 different URLs to verify TestNG execution order with different inputs

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