Allow username display to be case-insensitive

• We want to store a case-sensitive version of usernames for display both in the URL and on the profile itself. This is how GitHub, Twitter, and many other services operate.

Twitter example:

What this means as a fix:

• Add an additional key usernameDisplay in the user schema:

   {
   ...
   "properties": {
       ...
       "username": {
         "type": "string",
         "index": {
           "mongodb": {
             "unique": true,
             "background": true
           }
         },
         "require": true
       },
      "usernameDisplay": {
   	  "type": "string",
   	  ...
   	}
   ...
  

• This new usernameDisplay key will default to user.username on user creation.

• When a user updates their user name in the settings page, we fetch & update the usernameDisplay key. We also update the username key to its lowercase equivalent from the usernameDisplay key in the api-server side logic.

• The URL lookup and for a username should still default to the username lowercase.

• When the profile page is rendered, the display will render the usernameDisplay instead, but should fallback to the username in case its null or empty (existing users will not have this key on db)

_Originally posted by @QuincyLarson in https://github.com/freeCodeCamp/freeCodeCamp/issues/19346#issuecomment-458199335_

[salma71]

I’m interested too. If you like we can work together

[ojeytonwilliams]

Hi @veedata, yes, definitely. We have some contribution docs that help with getting started.