GenID

var genId = require('gen-id')('nnnnnnnc')
  , orderId = genId.generate()

console.log(orderId)

Initial available formats:

• n - numeric [0-9]
• a - alphabetical [a-z]
• A - alphabetical (case inclusive) [a-zA-Z]
• h - hexadecimal [0-9a-f]
• x - alpha-numeric [0-9a-z]
• X - alpha-numeric (case inclusive) [0-9a-zA-Z]
• c - checksum

You can change the format at any point by using genId.setFormat()