fetch.js

/*
Copyright (c) 2014-2016 GitHub, Inc.

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/


(function(self) {
  'use strict';

   if (self.fetch) {
     return
   }

  var support = {
    searchParams: 'URLSearchParams' in self,
    iterable: 'Symbol' in self && 'iterator' in Symbol,
    blob: 'FileReader' in self && 'Blob' in self && (function() {
      try {
        new Blob()
        return true
      } catch(e) {
        return false
      }
    })(),
    formData: 'FormData' in self,
    arrayBuffer: 'ArrayBuffer' in self
  }

  if (support.arrayBuffer) {
    var viewClasses = [
      '[object Int8Array]',
      '[object Uint8Array]',
      '[object Uint8ClampedArray]',
      '[object Int16Array]',
      '[object Uint16Array]',
      '[object Int32Array]',
      '[object Uint32Array]',
      '[object Float32Array]',
      '[object Float64Array]'
    ]

    var isDataView = function(obj) {
      return obj && DataView.prototype.isPrototypeOf(obj)
    }

    var isArrayBufferView = ArrayBuffer.isView || function(obj) {
      return obj && viewClasses.indexOf(Object.prototype.toString.call(obj)) > -1
    }
  }

  function normalizeName(name) {
    if (typeof name !== 'string') {
      name = String(name)
    }
    if (/[^a-z0-9\-#$%&'*+.\^_`|~]/i.test(name)) {
      throw new TypeError('Invalid character in header field name')
    }
    return name.toLowerCase()
  }

  function normalizeValue(value) {
    if (typeof value !== 'string') {
      value = String(value)
    }
    return value
  }

  // Build a destructive iterator for the value list
  function iteratorFor(items) {
    var iterator = {
      next: function() {
        var value = items.shift()
        return {done: value === undefined, value: value}
      }
    }

    if (support.iterable) {
      iterator[Symbol.iterator] = function() {
        return iterator
      }
    }

    return iterator
  }

  function Headers(headers) {
    this.map = {}

    if (headers instanceof Headers) {
      headers.forEach(function(value, name) {
        this.append(name, value)
      }, this)
    } else if (Array.isArray(headers)) {
      headers.forEach(function(header) {
        this.append(header[0], header[1])
      }, this)
    } else if (headers) {
      Object.getOwnPropertyNames(headers).forEach(function(name) {
        this.append(name, headers[name])
      }, this)
    }
  }

  Headers.prototype.append = function(name, value) {
    name = normalizeName(name)
    value = normalizeValue(value)
    var oldValue = this.map[name]
    this.map[name] = oldValue ? oldValue+','+value : value
  }

  Headers.prototype['delete'] = function(name) {
    delete this.map[normalizeName(name)]
  }

  Headers.prototype.get = function(name) {
    name = normalizeName(name)
    return this.has(name) ? this.map[name] : null
  }

  Headers.prototype.has = function(name) {
    return this.map.hasOwnProperty(normalizeName(name))
  }

  Headers.prototype.set = function(name, value) {
    this.map[normalizeName(name)] = normalizeValue(value)
  }

  Headers.prototype.forEach = function(callback, thisArg) {
    for (var name in this.map) {
      if (this.map.hasOwnProperty(name)) {
        callback.call(thisArg, this.map[name], name, this)
      }
    }
  }

  Headers.prototype.keys = function() {
    var items = []
    this.forEach(function(value, name) { items.push(name) })
    return iteratorFor(items)
  }

  Headers.prototype.values = function() {
    var items = []
    this.forEach(function(value) { items.push(value) })
    return iteratorFor(items)
  }

  Headers.prototype.entries = function() {
    var items = []
    this.forEach(function(value, name) { items.push([name, value]) })
    return iteratorFor(items)
  }

  if (support.iterable) {
    Headers.prototype[Symbol.iterator] = Headers.prototype.entries
  }

  function consumed(body) {
    if (body.bodyUsed) {
      return Promise.reject(new TypeError('Already read'))
    }
    body.bodyUsed = true
  }

  function fileReaderReady(reader) {
    return new Promise(function(resolve, reject) {
      reader.onload = function() {
        resolve(reader.result)
      }
      reader.onerror = function() {
        reject(reader.error)
      }
    })
  }

  function readBlobAsArrayBuffer(blob) {
    var reader = new FileReader()
    var promise = fileReaderReady(reader)
    reader.readAsArrayBuffer(blob)
    return promise
  }

  function readBlobAsText(blob) {
    var reader = new FileReader()
    var promise = fileReaderReady(reader)
    reader.readAsText(blob)
    return promise
  }

  function readArrayBufferAsText(buf) {
    var view = new Uint8Array(buf)
    var chars = new Array(view.length)

    for (var i = 0; i < view.length; i++) {
      chars[i] = String.fromCharCode(view[i])
    }
    return chars.join('')
  }

  function bufferClone(buf) {
    if (buf.slice) {
      return buf.slice(0)
    } else {
      var view = new Uint8Array(buf.byteLength)
      view.set(new Uint8Array(buf))
      return view.buffer
    }
  }

  function Body() {
    this.bodyUsed = false

    this._initBody = function(body) {
      this._bodyInit = body
      if (!body) {
        this._bodyText = ''
      } else if (typeof body === 'string') {
        this._bodyText = body
      } else if (support.blob && Blob.prototype.isPrototypeOf(body)) {
        this._bodyBlob = body
      } else if (support.formData && FormData.prototype.isPrototypeOf(body)) {
        this._bodyFormData = body
      } else if (support.searchParams && URLSearchParams.prototype.isPrototypeOf(body)) {
        this._bodyText = body.toString()
      } else if (support.arrayBuffer && support.blob && isDataView(body)) {
        this._bodyArrayBuffer = bufferClone(body.buffer)
        // IE 10-11 can't handle a DataView body.
        this._bodyInit = new Blob([this._bodyArrayBuffer])
      } else if (support.arrayBuffer && (ArrayBuffer.prototype.isPrototypeOf(body) || isArrayBufferView(body))) {
        this._bodyArrayBuffer = bufferClone(body)
      } else {
        throw new Error('unsupported BodyInit type')
      }

      if (!this.headers.get('content-type')) {
        if (typeof body === 'string') {
          this.headers.set('content-type', 'text/plain;charset=UTF-8')
        } else if (this._bodyBlob && this._bodyBlob.type) {
          this.headers.set('content-type', this._bodyBlob.type)
        } else if (support.searchParams && URLSearchParams.prototype.isPrototypeOf(body)) {
          this.headers.set('content-type', 'application/x-www-form-urlencoded;charset=UTF-8')
        }
      }
    }

    if (support.blob) {
      this.blob = function() {
        var rejected = consumed(this)
        if (rejected) {
          return rejected
        }

        if (this._bodyBlob) {
          return Promise.resolve(this._bodyBlob)
        } else if (this._bodyArrayBuffer) {
          return Promise.resolve(new Blob([this._bodyArrayBuffer]))
        } else if (this._bodyFormData) {
          throw new Error('could not read FormData body as blob')
        } else {
          return Promise.resolve(new Blob([this._bodyText]))
        }
      }

      this.arrayBuffer = function() {
        if (this._bodyArrayBuffer) {
          return consumed(this) || Promise.resolve(this._bodyArrayBuffer)
        } else {
          return this.blob().then(readBlobAsArrayBuffer)
        }
      }
    }

    this.text = function() {
      var rejected = consumed(this)
      if (rejected) {
        return rejected
      }

      if (this._bodyBlob) {
        return readBlobAsText(this._bodyBlob)
      } else if (this._bodyArrayBuffer) {
        return Promise.resolve(readArrayBufferAsText(this._bodyArrayBuffer))
      } else if (this._bodyFormData) {
        throw new Error('could not read FormData body as text')
      } else {
        return Promise.resolve(this._bodyText)
      }
    }

    if (support.formData) {
      this.formData = function() {
        return this.text().then(decode)
      }
    }

    this.json = function() {
      return this.text().then(JSON.parse)
    }

    return this
  }

  // HTTP methods whose capitalization should be normalized
  var methods = ['DELETE', 'GET', 'HEAD', 'OPTIONS', 'POST', 'PUT']

  function normalizeMethod(method) {
    var upcased = method.toUpperCase()
    return (methods.indexOf(upcased) > -1) ? upcased : method
  }

  function Request(input, options) {
    options = options || {}
    var body = options.body

    if (input instanceof Request) {
      if (input.bodyUsed) {
        throw new TypeError('Already read')
      }
      this.url = input.url
      this.credentials = input.credentials
      if (!options.headers) {
        this.headers = new Headers(input.headers)
      }
      this.method = input.method
      this.mode = input.mode
      if (!body && input._bodyInit != null) {
        body = input._bodyInit
        input.bodyUsed = true
      }
    } else {
      this.url = String(input)
    }

    this.credentials = options.credentials || this.credentials || 'omit'
    if (options.headers || !this.headers) {
      this.headers = new Headers(options.headers)
    }
    this.method = normalizeMethod(options.method || this.method || 'GET')
    this.mode = options.mode || this.mode || null
    this.referrer = null

    if ((this.method === 'GET' || this.method === 'HEAD') && body) {
      throw new TypeError('Body not allowed for GET or HEAD requests')
    }
    this._initBody(body)
  }

  Request.prototype.clone = function() {
    return new Request(this, { body: this._bodyInit })
  }

  function decode(body) {
    var form = new FormData()
    body.trim().split('&').forEach(function(bytes) {
      if (bytes) {
        var split = bytes.split('=')
        var name = split.shift().replace(/\+/g, ' ')
        var value = split.join('=').replace(/\+/g, ' ')
        form.append(decodeURIComponent(name), decodeURIComponent(value))
      }
    })
    return form
  }

  function parseHeaders(rawHeaders) {
    var headers = new Headers()
    // Replace instances of \r\n and \n followed by at least one space or horizontal tab with a space
    // https://tools.ietf.org/html/rfc7230#section-3.2
    var preProcessedHeaders = rawHeaders.replace(/\r?\n[\t ]+/g, ' ')
    preProcessedHeaders.split(/\r?\n/).forEach(function(line) {
      var parts = line.split(':')
      var key = parts.shift().trim()
      if (key) {
        var value = parts.join(':').trim()
        headers.append(key, value)
      }
    })
    return headers
  }

  Body.call(Request.prototype)

  function Response(bodyInit, options) {
    if (!options) {
      options = {}
    }

    this.type = 'default'
    this.status = options.status === undefined ? 200 : options.status
    this.ok = this.status >= 200 && this.status < 300
    this.statusText = 'statusText' in options ? options.statusText : 'OK'
    this.headers = new Headers(options.headers)
    this.url = options.url || ''
    this._initBody(bodyInit)
  }

  Body.call(Response.prototype)

  Response.prototype.clone = function() {
    return new Response(this._bodyInit, {
      status: this.status,
      statusText: this.statusText,
      headers: new Headers(this.headers),
      url: this.url
    })
  }

  Response.error = function() {
    var response = new Response(null, {status: 0, statusText: ''})
    response.type = 'error'
    return response
  }

  var redirectStatuses = [301, 302, 303, 307, 308]

  Response.redirect = function(url, status) {
    if (redirectStatuses.indexOf(status) === -1) {
      throw new RangeError('Invalid status code')
    }

    return new Response(null, {status: status, headers: {location: url}})
  }

  self.Headers = Headers
  self.Request = Request
  self.Response = Response

  self.fetch = function(input, init) {
    return new Promise(function(resolve, reject) {
      var request = new Request(input, init)
      var xhr = new XMLHttpRequest()

      xhr.onload = function() {
        var options = {
          status: xhr.status,
          statusText: xhr.statusText,
          headers: parseHeaders(xhr.getAllResponseHeaders() || '')
        }
        options.url = 'responseURL' in xhr ? xhr.responseURL : options.headers.get('X-Request-URL')
        var body = 'response' in xhr ? xhr.response : xhr.responseText
        resolve(new Response(body, options))
      }

      xhr.onerror = function() {
        reject(new TypeError('Network request failed'))
      }

      xhr.ontimeout = function() {
        reject(new TypeError('Network request failed'))
      }

      xhr.open(request.method, request.url, true)

      if (request.credentials === 'include') {
        xhr.withCredentials = true
      } else if (request.credentials === 'omit') {
        xhr.withCredentials = false
      }

      if ('responseType' in xhr && support.blob) {
        xhr.responseType = 'blob'
      }

      request.headers.forEach(function(value, name) {
        xhr.setRequestHeader(name, value)
      })

      xhr.send(typeof request._bodyInit === 'undefined' ? null : request._bodyInit)
    })
  }
  self.fetch.polyfill = true
})(typeof self !== 'undefined' ? self : this);