Password strength with regex in Ruby

password_strength.rb

# example of using lookahead assertion to test password strength

# test if a given string contains at least a lowercase letter, a uppercase, a digit, a special char and 8+ chars
strong = "123ABCabc-"
strong[/^(?=.*[a-zA-Z])(?=.*[0-9])(?=.*[\W]).{8,}$/]

# test if a given string contains at least a lowercase letter, a uppercase, a digit and 8+ chars
medium = "123ABCabc"
medium[/^(?=.*[a-zA-Z])(?=.*[0-9]).{8,}$/]

Use this instead:

/\A(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*\W).{8,}\z/