index.js

var Promise = require('any-promise')

module.exports = function (stream, done) {
  if (!stream) {
    // no arguments, meaning stream = this
    stream = this
  } else if (typeof stream === 'function') {
    // stream = this, callback passed
    done = stream
    stream = this
  }

  var deferred
  if (!stream.readable) deferred = Promise.resolve([])
  else deferred = new Promise(function (resolve, reject) {
    // stream is already ended
    if (!stream.readable) return resolve([])

    var arr = []

    stream.on('data', onData)
    stream.on('end', onEnd)
    stream.on('error', onError)
    stream.on('close', onClose)

    function onData(doc) {
      arr.push(doc)
    }

    function onEnd(err) {
      resolve(arr)
      cleanup()
    }

    function onError(err) {
      reject(err)
      cleanup()
    }

    function onClose() {
      resolve(arr)
      cleanup()
    }

    function cleanup() {
      arr = null
      stream.removeListener('data', onData)
      stream.removeListener('end', onEnd)
      stream.removeListener('error', onEnd)
      stream.removeListener('close', onClose)
    }
  })

  if (typeof done === 'function') {
    deferred.then(function (arr) { done(null, arr) }, done)
  }

  return deferred
}