plugin.js

'use strict'

const fp = require('fastify-plugin')
const { createTransport } = require('nodemailer')

function fastifyMailer (fastify, options, next) {
  const { defaults, namespace, transport } = options

  if (!transport) {
    return next(new Error('You must provide a valid transport configuration object, connection url or a transport plugin instance'))
  }

  let transporter

  try {
    if (!defaults) {
      transporter = createTransport(transport)
    } else {
      transporter = createTransport(transport, defaults)
    }
  } catch (error) {
    return next(error)
  }

  if (namespace) {
    if (transporter[namespace]) {
      return next(new Error(`fastify-mailer '${namespace}' is a reserved keyword`))
    } else if (!fastify.mailer) {
      fastify.decorate('mailer', Object.create(null))
    } else if (Object.prototype.hasOwnProperty.call(fastify.mailer, namespace)) {
      return next(
        new Error(`fastify-mailer '${namespace}' instance name has already been registered`)
      )
    }

    fastify.mailer[namespace] = transporter
  } else {
    if (fastify.mailer) {
      return next(new Error('fastify-mailer has already been registered'))
    } else {
      fastify.decorate('mailer', transporter)
    }
  }

  next()
}

module.exports = fp(fastifyMailer, {
  fastify: '>=2.0.0',
  name: 'fastify-mailer'
})