nodejs/deps/npm/node_modules/npm-user-validate/lib/index.js

exports.email = email
exports.pw = pw
exports.username = username
var requirements = exports.requirements = {
  username: {
    length: 'Name length must be less than or equal to 214 characters long',
    lowerCase: 'Name must be lowercase',
    urlSafe: 'Name may not contain non-url-safe chars',
    dot: 'Name may not start with "."',
    illegal: 'Name may not contain illegal character',
  },
  password: {},
  email: {
    length: 'Email length must be less then or equal to 254 characters long',
    valid: 'Email must be an email address',
  },
}

var illegalCharacterRe = new RegExp('([' + [
  "'",
].join() + '])')

function username (un) {
  if (un !== un.toLowerCase()) {
    return new Error(requirements.username.lowerCase)
  }

  if (un !== encodeURIComponent(un)) {
    return new Error(requirements.username.urlSafe)
  }

  if (un.charAt(0) === '.') {
    return new Error(requirements.username.dot)
  }

  if (un.length > 214) {
    return new Error(requirements.username.length)
  }

  var illegal = un.match(illegalCharacterRe)
  if (illegal) {
    return new Error(requirements.username.illegal + ' "' + illegal[0] + '"')
  }

  return null
}

function email (em) {
  if (em.length > 254) {
    return new Error(requirements.email.length)
  }
  if (!em.match(/^[^@]+@.+\..+$/)) {
    return new Error(requirements.email.valid)
  }

  return null
}

function pw () {
  return null
}