add-to-slack.js

module.exports = function addToSlack() {
  let scope = 'commands,bot'
  let clientID = process.env.SLACK_CLIENT_ID
  let redirect = process.env.SLACK_INSTALL_REDIRECT
  let href = `https://slack.com/oauth/authorize?scope=${scope}&client_id=${clientID}&redirect_uri=${redirect}`
  return `
<a href=${href}>
<img alt="Add to Slack" 
  height="40" 
  width="139" 
  src="https://platform.slack-edge.com/img/add_to_slack.png" 
  srcset="https://platform.slack-edge.com/img/add_to_slack.png 1x, https://platform.slack-edge.com/img/add_to_slack@2x.png 2x">
</a>
`
}