如何在经过验证的页面上测试javascript隐藏/显示行为?

Context: When a user is logged and consulting his own profile, he can click on his avatar, this click displays a Dropdown menu with an option 'Upload avatar'. When the user clicks on this option, it opens a modal with a form for uploading a new image for the avatar. I am using twitter bootstrap to handle the dropdown (and the modal). When a user is logged and consulting h