One of our client want functionality to change username in edit profile which is easy. We are using pathauto module for pretty URL in Drupal7.
I faced two issues when changing username. which are explained here..
We are using username paths (/users/[username]). After changing a username the url alias doesn’t change and the user edit page doesn’t have an option to change it manually.
We are using username before nodes urls. for after changing username Node uel alias does not change automatically.