Where do you use Polymorphism in java? Explain W.R.T Automation.

In automation testing with Java—especially when using frameworks like Selenium, TestNG, or JUnit—polymorphism becomes a quiet powerhouse behind cleaner, more scalable, and flexible test code. Here’s where it really comes into play:

1. Test Framework Design (Abstract Test Classes & Interfaces)

You can define an abstract class or interface that sets the “rules” for all test cases:

public interface TestScenario {
    void setup();
    void executeTest();
    void teardown();
}

Now multiple classes implement different versions of this scenario:

public class LoginTest implements TestScenario {
    public void setup() { /* login setup */ }
    public void executeTest() { /* test login */ }
    public void teardown() { /* clean up */ }
}

You can store and run them like this:

TestScenario test = new LoginTest();
test.executeTest();  // Polymorphic call

2. Page Object Model (POM) Implementation

One of the best uses of runtime polymorphism in testing:

• Base class: BasePage
• Subclasses: LoginPage, DashboardPage, SearchPage, etc.

public class BasePage {
    WebDriver driver;
    public BasePage(WebDriver driver) {
        this.driver = driver;
    }

    public void clickElement(By locator) {
        driver.findElement(locator).click();
    }
}

Each page inherits from BasePage, but adds its own methods. You can use the base class type to handle any page generically.

3. Driver Abstraction (Interface for Different Browsers)

Let’s say you define:

public interface DriverManager {
    WebDriver getDriver();
}

Then provide different implementations:

public class ChromeManager implements DriverManager {
    public WebDriver getDriver() {
        return new ChromeDriver();
    }
}

public class FirefoxManager implements DriverManager {
    public WebDriver getDriver() {
        return new FirefoxDriver();
    }
}

Now your test code doesn’t care which browser is running:

DriverManager manager = new ChromeManager();
WebDriver driver = manager.getDriver();

Switching to Firefox? Just change the instantiation.

4. Custom Assertions or Reporters

You might define a Reporter interface and plug in different implementations: HTML reports, logs, dashboards—polymorphism lets you switch without touching your test logic.

Why It Matters

• Easier maintenance: Swap components without breaking test cases
• Cleaner test code: Reduces duplication
• Extensibility: Add new features with less refactoring