smtp-server-as-promised

smtp-server-as-promised

This module provides promisified version of smtp-server module. The API is the same as for smtp-server, except listen method which return Promise object and callback options which are Promise objects.

Requirements

This module requires Node >= 6.

Installation

npm install smtp-server-as-promised

Additionally for Typescript:

npm install -D @types/node @types/nodemailer

Transpiling this module with own settings in tsconfig.json:

{
  "compilerOptions": {
    "paths": {
      "smtp-server-as-promised": ["node_modules/smtp-server-as-promised/src/smtp-server-as-promised"]
    }
  }
}

Usage

smtp-server-as-promised can be used like standard smtp-server module:

const { SMTPServerAsPromised } = require('smtp-server-as-promised')

Typescript:

import SMTPServerAsPromised from 'smtp-server-as-promised'

constructor

const server = new SMTPServerAsPromised(options)

Create new SMTPServer instance.

Example:

const server = new SMTPServerAsPromised({
  onConnect, onMailFrom, onData, onError
})

Options are the same as for original smtp-server constructor. Callback handlers are Promise objects or async functions:

onConnect

async function onConnect (session) {
  console.log(`[${session.id}] onConnect`)
}

onAuth

async function onAuth (auth, session) {
  if (auth.method === 'PLAIN' && auth.username === 'username' && auth.password === 'password') {
    return {user: auth.username}
  } else {
    throw new Error('Invalid username or password')
  }
}

This method must return the object with user property.

onMailFrom

async function onMailFrom (from, session) {
  console.log(`[${session.id}] onMailFrom ${from.address}`)
  if (from.address.split('@')[1] === 'spammer.com') {
    throw new Error('we do not like spam!')
  }
}

An errors can be thrown and then are handled by server in response message.

onRcptTo

async function onRcptTo (to, session) {
  console.log(`[${session.id}] onRcptTo ${to.address}`)
  if (from.address.split('@')[1] === 'spammer.com') {
    throw new Error('we do not like spam!')
  }
}

onData

async function onData (stream, session) {
  console.log(`[${session.id}] onData started`)
  session.messageLength = 0

  for (let chunk; (chunk = await stream.read());) {
    console.log(`[${session.id}] onData got data chunk ${chunk.length} bytes`)
    session.messageLength += chunk.length
  }

  console.log(`[${session.id}] onData finished after reading ${session.messageLength} bytes`)
}

stream object is a standard stream.Readable object.

Warning: if an error occures in onData handler, stream have to be consumed before return from function.

Example:

const { NullWritable } = require('null-writable')

async function onData (stream, session) {
  try {
    throw new Error('Something bad happened')
  } catch (e) {
    stream.pipe(new NullWritable())  // read it to the end
    throw e  // rethrow original error
  }
}

onError

async function onError (e) {
  console.log('Server error:', e)
}

listen

const promise = server.listen(options)

Start the server instance. Argument is the same as for net.listen method. This method returns promise which resolves to address value.

Example:

async function main () {
  const address = await server.listen({ port: 2525 })
  console.log(`Listening on [${address.address}]:${address.port}`)
}

close

const promise = server.close()

Stop the server from accepting new connections.

Example:

async function main () {
  // ...
  await server.close()
  console.log(`Server was stopped`)
}

updateSecureContext

server.updateSecureContext(options)

Update TLS secure context.

Example:

server.updateSecureContext({ key: tlsKeyPem })

License

Copyright (c) 2016-2018 Piotr Roszatycki [e-mail]

MIT

Changelog

v4.0.0 2018-09-09

• Rewritten in Typescript.
• Requires Node >= 6
• Changed syntax for import.