New Feature: add validation rule for username in framework

[smarcelloc]

When exploring the Laravel ecosystem, the robustness of the validation rules already available is evident. However, I see a opportunity for improvement: the inclusion of a specific validation rule for field username. In my experience at the company I work for, where user management is essential, we often ourselves creating custom rules to validate the username field. Not only my company where I work, other systems use username like github in page register. I believe that the user validation rule can add value to the Laravel community.

Functionality Details:

• The username can contain letters from A to Z (upper or lower case), numbers, dash (-), underscore (_) and period (.).
• Additionally, it must start with letters and numbers.

Examples

Valid:

• john_doe123
• alice.smith
• 1johndoe

Invalid:

• _john_doe (does not start with letter or number)
• john@doe (contains an invalid '@' character)

[shaedrich]

I doubt, there is a universal understanding when it comes down to the specific specification of a "username". Different systems would have different patterns and requirements for their usernames.

[allanmcarvalho]

But about this we can do like the password strength validator, so, we can customize it's behavior

[shaedrich]

Maybe, functionality can be extracted into a more generic PatternRule or the like 🤔