Selenium Webdriver - verify text box write-protected?

The WebElement interface has a function called isEnabled.

You can try to write something via sendkeys() and check that value attribute of textbox has not been changed.

1. isEnabled() does not have any common things to readonly.
2. String attribute = element.getAttribute("readonly"); will not fail your test even "readonly" is absent. In this case it returns null, but we need exception.

Use like this:

    WebElement some_element = driver.findElement(By.id("some_id"));
    String readonly = some_element.getAttribute("readonly");
    Assert.assertNotNull(readonly);

Do NOT verify getAttribute("readonly").equals("true") or similar, in different browsers it can be different as well. (readonly="readonly" in IE, readonly="" in FF, etc.)