Checking if a password field is present in Selenium
How to use Selenium to check if the password field is present
Many people fall into the (understandable) trap of treating Password fields like Text fields when testing them in Selenium.
If you have made this mistake then you may be stuck wondering about how to test for masking in the field (like this chap was) the answer, of course, is to assert that input of type password and id of whatever exists on the page.