A function which generates a password containing at least one lowercase letter, one uppercase letter and a digit.

password_generator.coffee

_ = require('lodash')

PasswordGenerator = (length = 20) ->
  _.map(_.shuffle(_.range(length)), (n) ->
    switch n % 3
      when 0 # A digit
        Math.floor(Math.random() * 9).toString()
      when 1 # A lowercase letter
        String.fromCharCode(Math.floor(Math.random() * 26) + 97)
      when 2 # An uppercase letter
        String.fromCharCode(Math.floor(Math.random() * 26) + 65)
  ).join('')