HTML5 form validation

[SiKing]

Has anyone managed to get at HTML5 form validation.

Sample page: https://getbootstrap.com/docs/5.0/forms/validation/#browser-defaults

If you click on "Submit form" (without filling anything out), you will see the "Please fill out this field." popup.

Can you detect the popup with Selenium?

[SiKing]

Got it figured out. You can use something like this:

public String getPopupError() {
    JavascriptExecutor executor = (JavascriptExecutor) driver;

    // Note that before the form is submitted, arguments[0].validity.valid == false!
    if (!(Boolean) executor.executeScript("return arguments[0].validity.valid;", username)) {
        log.warn("Username: {}", executor.executeScript("return arguments[0].validationMessage;", username));
        return (String) executor.executeScript("return arguments[0].validationMessage;", username);
    }

    if (!(Boolean) executor.executeScript("return arguments[0].validity.valid;", password)) {
        log.warn("Password: {}", executor.executeScript("return arguments[0].validationMessage;", password));
        return (String) executor.executeScript("return arguments[0].validationMessage;", password);
    }

    return null;
}

In the above case username and password are WebElement.