Selenium test - Firefox alert disappearing immediately

Question

I am writing a Selenium test on Firefox that deals with an alert. The alert appears for a fraction of a second when the test is run, but when done manually the alert persists. C

Answer 1

There are 3 states for UnexpectedAlertBehaviour:

1. ACCEPT - Accepts the alert
2. DISMISS - Closes/Cancels the alert
3. IGNORE - Neither accepts nor closes the alert

DesiredCapabilities dc = new DesiredCapabilities();
dc.setCapability(CapabilityType.UNEXPECTED_ALERT_BEHAVIOUR, UnexpectedAlertBehaviour.IGNORE);
driver = new FirefoxDriver(dc);

Then you can handle the alert by performing the operation that triggers the alert and catching it as an expected exception:

try {
    click(myButton);
} catch (UnhandledAlertException f) {
    try {
        Alert alert = driver.switchTo().alert();
        String alertText = alert.getText();
        System.out.println("Alert data: " + alertText);
        alert.accept();
    } catch (NoAlertPresentException e) {
        e.printStackTrace();
    }
}

Answer 2

The chosen answer worked for me, but it seems that FirefoxDriver(org.openqa.selenium.Capabilities) is deprecated. The working alternative is:

FirefoxOptions firefoxOptions = new FirefoxOptions();
firefoxOptions.setCapability(CapabilityType.UNEXPECTED_ALERT_BEHAVIOUR, UnexpectedAlertBehaviour.IGNORE);
driver = new FirefoxDriver(firefoxOptions);

Answer 3

I don't think the 'alerts.disableSlidingEffect' Firefox profile option should be causing the alert to disappear - Instead, try creating your WebDriver instance using the unexpectedalertbehaviour capability set to 'ignore'.