_read.js

var http = require('http')
var https = require('https')
var url = require('url')
var qs = require('querystring')

module.exports = function _read(httpMethod, options, callback) {

  // deep copy options
  options = JSON.parse(JSON.stringify(options))

  // alias body = data
  if (options.body && !options.data) {
    options.data = options.body
  }

  // require options.url or fail noisily
  if (!options.url) {
    throw Error('options.url required')
  }

  // setup promise if there is no callback
  var promise
  if (!callback) {
    promise = new Promise(function(res, rej) {
      callback = function(err, result) {
        err ? rej(err) : res(result)
      }
    })
  }

  // parse out the options from options.url
  var opts = url.parse(options.url)
  var method = opts.protocol === 'https:' ? https.request : http.request
  var defaultContentType = 'application/json; charset=utf-8'

  // check for additional query params
  if (options.data) {
    var isSearch = !!opts.search
    options.url += (isSearch? '&' : '?') + qs.stringify(options.data)
    opts = url.parse(options.url)
  }

  // add timeout if it exists
  if (options.timeout) {
    opts.timeout = options.timeout
  }

  // wrangle defaults
  opts.method = httpMethod
  opts.headers = options.headers || {}
  opts.headers['user-agent'] = opts.headers['user-agent'] || opts.headers['User-Agent'] || 'tiny-http'
  opts.headers['content-type'] = opts.headers['content-type'] || opts.headers['Content-Type'] || defaultContentType

  // make a request
  var req = method(opts, function _res(res) {
    var raw = [] // keep our buffers here
    var ok = res.statusCode >= 200 && res.statusCode < 303

    res.on('data', function _data(chunk) {
      raw.push(chunk)
    })

    res.on('end', function _end() {
      var err = null
      var result = null
      var isJSON = res.headers['content-type'] &&
                  (res.headers['content-type'].startsWith('application/json') ||
                   res.headers['content-type'].match(/^application\/.*json/))
      try {
        result = Buffer.concat(raw)

        if (!options.buffer) {
          var strRes = result.toString()
          result = strRes && isJSON ? JSON.parse(strRes) : strRes
        }
      }
      catch(e) {
        err = e
      }

      if (!ok) {
        err = Error('GET failed with: ' + res.statusCode)
        err.raw = res
        err.body = isJSON? JSON.stringify(result) : result.toString()
        err.statusCode = res.statusCode
        callback(err)
      }
      else {
        callback(err, {body:result, headers:res.headers})
      }
    })
  })

  req.on('error', callback)
  req.end()

  return promise
}