Parallel Execution and Thread Safety

<!-- Run each <test> tag in its own thread -->
<suite name="Parallel Suite" parallel="tests" thread-count="2">

    <test name="Banking">  <!-- Thread 1 -->
        <classes>
            <class name="com.autopractice.tests.BankingLoginTest" />
            <class name="com.autopractice.tests.BankingDashboardTest" />
        </classes>
    </test>

    <test name="Shopping">  <!-- Thread 2 -->
        <classes>
            <class name="com.autopractice.tests.ShoppingCartTest" />
            <class name="com.autopractice.tests.ShoppingCheckoutTest" />
        </classes>
    </test>

</suite>

<!-- Run each CLASS in its own thread -->
<suite name="Class Parallel" parallel="classes" thread-count="4">
    <test name="All Tests">
        <classes>
            <class name="com.autopractice.tests.BankingLoginTest" />
            <class name="com.autopractice.tests.BankingDashboardTest" />
            <class name="com.autopractice.tests.ShoppingCartTest" />
            <class name="com.autopractice.tests.ShoppingCheckoutTest" />
        </classes>
    </test>
</suite>

public class BaseTest {
    private static ThreadLocal<WebDriver> driverThread =
        new ThreadLocal<>();
    private static ThreadLocal<WebDriverWait> waitThread =
        new ThreadLocal<>();

    @BeforeMethod
    public void setUp() {
        WebDriver driver = new ChromeDriver();
        driver.manage().window().maximize();
        driverThread.set(driver);  // Store in ThreadLocal
        waitThread.set(new WebDriverWait(driver, Duration.ofSeconds(10)));
    }

    public WebDriver getDriver() {
        return driverThread.get();  // Get THIS thread's driver
    }

    public WebDriverWait getWait() {
        return waitThread.get();
    }

    @AfterMethod
    public void tearDown() {
        WebDriver driver = driverThread.get();
        if (driver != null) {
            driver.quit();
            driverThread.remove();  // Prevent memory leaks
            waitThread.remove();
        }
    }
}

// Test class uses getDriver() instead of direct field access
public class BankingLoginTest extends BaseTest {

    @Test(groups = {"smoke"})
    public void testSuccessfulLogin() {
        getDriver().get("https://www.testerrank.com/banking");
        getDriver().findElement(By.id("username")).sendKeys("admin");
        getDriver().findElement(By.id("password")).sendKeys("admin123");
        getDriver().findElement(
            By.cssSelector("button[type='submit']")).click();

        getWait().until(ExpectedConditions.urlContains("/dashboard"));
        Assert.assertTrue(
            getDriver().getCurrentUrl().contains("/dashboard")
        );
    }
}