Unexpected alert handling in Selenium Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output when an unexpected alert appears?

Consider the following Selenium Java code snippet. What will be the output when an unexpected alert pops up during the click action?

Selenium Java

try {
    driver.findElement(By.id("submitBtn")).click();
    System.out.println("Clicked successfully");
} catch (UnhandledAlertException e) {
    System.out.println("Alert detected and handled");
}

A Alert detected and handled

B Clicked successfully

C No output, test hangs

D Throws NoSuchElementException

💡 Hint

Think about what happens when an alert blocks interaction in Selenium.

When an unexpected alert appears, Selenium throws UnhandledAlertException. The catch block prints "Alert detected and handled".

❓ assertion

intermediate

Which assertion correctly verifies alert text?

You want to verify that an alert's text is exactly "Session expired". Which assertion is correct?

Selenium Java

Alert alert = driver.switchTo().alert();
String alertText = alert.getText();

A assertEquals(alertText, "Session expired");

B assertTrue(alertText.contains("Session expired"));

C assertFalse(alertText.equals("Session expired"));

D assertNull(alertText);

💡 Hint

Exact match requires equality assertion.

assertEquals checks exact equality, which is needed here. Other options check contains, false equality, or null which are incorrect.

🔧 Debug

advanced

Why does this code fail to handle an unexpected alert?

This code tries to accept an unexpected alert but fails with UnhandledAlertException. Identify the cause.

Selenium Java

try {
    driver.findElement(By.id("saveBtn")).click();
    driver.switchTo().alert().accept();
} catch (NoAlertPresentException e) {
    System.out.println("No alert to accept");
}

A driver.findElement throws exception, not handled

B NoAlertPresentException is not caught properly

C accept() method is deprecated and causes failure

D Alert appears before click, click() throws UnhandledAlertException before switchTo().alert()

💡 Hint

Consider when the alert appears relative to the click.

If alert appears before click, the click() throws UnhandledAlertException because alert was blocking interaction. The code never reaches switchTo().alert(), and UnhandledAlertException is not caught.

❓ framework

advanced

Best practice to handle unexpected alerts in Selenium tests?

Which approach is best to handle unexpected alerts globally in Selenium Java tests?

A Ignore alerts and let tests fail to fix issues manually

B Wrap every click action in try-catch for UnhandledAlertException

C Use WebDriver event listeners to detect and accept alerts automatically

D Use Thread.sleep() before every action to wait for alerts

💡 Hint

Think about a scalable way to handle alerts without repeating code.

Event listeners allow centralized handling of alerts, improving maintainability and reducing code duplication.

🧠 Conceptual

expert

What happens if you ignore an unexpected alert in Selenium?

If a test encounters an unexpected alert and does not handle it, what is the most likely outcome?

A Test ignores alert and continues normally

B Test throws UnhandledAlertException and stops execution

C Alert automatically closes after timeout

D Test logs warning but passes

💡 Hint

Selenium blocks interaction when alert is present.

Selenium throws UnhandledAlertException when an unexpected alert blocks interaction, causing test failure unless handled.