slack-invite.js

import request from 'superagent'

export default function invite ({ org, token, email, channel }, fn){
  let data = { email, token }

  if (channel) {
    data.channels = channel
    data.ultra_restricted = 1
    data.set_active = true
  }

  request
  .post(`https://${org}.slack.com/api/users.admin.invite`)
  .type('form')
  .send(data)
  .end(function (err, res){
    if (err) return fn(err)
    if (200 != res.status) {
      fn(new Error(`Invalid response ${res.status}.`))
      return
    }

    // If the account that owns the token is not admin, Slack will oddly
    // return `200 OK`, and provide other information in the body. So we
    // need to check for the correct account scope and call the callback
    // with an error if it's not high enough.
    let {ok, error: providedError, needed} = res.body
    if (!ok) {
      if (providedError === 'missing_scope' && needed === 'admin') {
        fn(new Error(`Missing admin scope: The token you provided is for an account that is not an admin. You must provide a token from an admin account in order to invite users through the Slack API.`))
      } else if (providedError === 'already_invited') {
        fn(new Error('You have already been invited to Slack. Check for an email from feedback@slack.com.'))
      } else if (providedError === 'already_in_team') {
        fn(new Error(`Sending you to Slack...`))
      } else {
        fn(new Error(providedError))
      }
      return
    }

    fn(null)
  })
}