twitst4tz

twitter statistics web application
Log | Files | Refs | README | LICENSE

index.es.js (40940B)


      1 process.emitWarning("The .es.js file is deprecated. Use .mjs instead.");
      2 
      3 import Stream from 'stream';
      4 import http from 'http';
      5 import Url from 'url';
      6 import https from 'https';
      7 import zlib from 'zlib';
      8 
      9 // Based on https://github.com/tmpvar/jsdom/blob/aa85b2abf07766ff7bf5c1f6daafb3726f2f2db5/lib/jsdom/living/blob.js
     10 
     11 // fix for "Readable" isn't a named export issue
     12 const Readable = Stream.Readable;
     13 
     14 const BUFFER = Symbol('buffer');
     15 const TYPE = Symbol('type');
     16 
     17 class Blob {
     18 	constructor() {
     19 		this[TYPE] = '';
     20 
     21 		const blobParts = arguments[0];
     22 		const options = arguments[1];
     23 
     24 		const buffers = [];
     25 		let size = 0;
     26 
     27 		if (blobParts) {
     28 			const a = blobParts;
     29 			const length = Number(a.length);
     30 			for (let i = 0; i < length; i++) {
     31 				const element = a[i];
     32 				let buffer;
     33 				if (element instanceof Buffer) {
     34 					buffer = element;
     35 				} else if (ArrayBuffer.isView(element)) {
     36 					buffer = Buffer.from(element.buffer, element.byteOffset, element.byteLength);
     37 				} else if (element instanceof ArrayBuffer) {
     38 					buffer = Buffer.from(element);
     39 				} else if (element instanceof Blob) {
     40 					buffer = element[BUFFER];
     41 				} else {
     42 					buffer = Buffer.from(typeof element === 'string' ? element : String(element));
     43 				}
     44 				size += buffer.length;
     45 				buffers.push(buffer);
     46 			}
     47 		}
     48 
     49 		this[BUFFER] = Buffer.concat(buffers);
     50 
     51 		let type = options && options.type !== undefined && String(options.type).toLowerCase();
     52 		if (type && !/[^\u0020-\u007E]/.test(type)) {
     53 			this[TYPE] = type;
     54 		}
     55 	}
     56 	get size() {
     57 		return this[BUFFER].length;
     58 	}
     59 	get type() {
     60 		return this[TYPE];
     61 	}
     62 	text() {
     63 		return Promise.resolve(this[BUFFER].toString());
     64 	}
     65 	arrayBuffer() {
     66 		const buf = this[BUFFER];
     67 		const ab = buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
     68 		return Promise.resolve(ab);
     69 	}
     70 	stream() {
     71 		const readable = new Readable();
     72 		readable._read = function () {};
     73 		readable.push(this[BUFFER]);
     74 		readable.push(null);
     75 		return readable;
     76 	}
     77 	toString() {
     78 		return '[object Blob]';
     79 	}
     80 	slice() {
     81 		const size = this.size;
     82 
     83 		const start = arguments[0];
     84 		const end = arguments[1];
     85 		let relativeStart, relativeEnd;
     86 		if (start === undefined) {
     87 			relativeStart = 0;
     88 		} else if (start < 0) {
     89 			relativeStart = Math.max(size + start, 0);
     90 		} else {
     91 			relativeStart = Math.min(start, size);
     92 		}
     93 		if (end === undefined) {
     94 			relativeEnd = size;
     95 		} else if (end < 0) {
     96 			relativeEnd = Math.max(size + end, 0);
     97 		} else {
     98 			relativeEnd = Math.min(end, size);
     99 		}
    100 		const span = Math.max(relativeEnd - relativeStart, 0);
    101 
    102 		const buffer = this[BUFFER];
    103 		const slicedBuffer = buffer.slice(relativeStart, relativeStart + span);
    104 		const blob = new Blob([], { type: arguments[2] });
    105 		blob[BUFFER] = slicedBuffer;
    106 		return blob;
    107 	}
    108 }
    109 
    110 Object.defineProperties(Blob.prototype, {
    111 	size: { enumerable: true },
    112 	type: { enumerable: true },
    113 	slice: { enumerable: true }
    114 });
    115 
    116 Object.defineProperty(Blob.prototype, Symbol.toStringTag, {
    117 	value: 'Blob',
    118 	writable: false,
    119 	enumerable: false,
    120 	configurable: true
    121 });
    122 
    123 /**
    124  * fetch-error.js
    125  *
    126  * FetchError interface for operational errors
    127  */
    128 
    129 /**
    130  * Create FetchError instance
    131  *
    132  * @param   String      message      Error message for human
    133  * @param   String      type         Error type for machine
    134  * @param   String      systemError  For Node.js system error
    135  * @return  FetchError
    136  */
    137 function FetchError(message, type, systemError) {
    138   Error.call(this, message);
    139 
    140   this.message = message;
    141   this.type = type;
    142 
    143   // when err.type is `system`, err.code contains system error code
    144   if (systemError) {
    145     this.code = this.errno = systemError.code;
    146   }
    147 
    148   // hide custom error implementation details from end-users
    149   Error.captureStackTrace(this, this.constructor);
    150 }
    151 
    152 FetchError.prototype = Object.create(Error.prototype);
    153 FetchError.prototype.constructor = FetchError;
    154 FetchError.prototype.name = 'FetchError';
    155 
    156 let convert;
    157 try {
    158 	convert = require('encoding').convert;
    159 } catch (e) {}
    160 
    161 const INTERNALS = Symbol('Body internals');
    162 
    163 // fix an issue where "PassThrough" isn't a named export for node <10
    164 const PassThrough = Stream.PassThrough;
    165 
    166 /**
    167  * Body mixin
    168  *
    169  * Ref: https://fetch.spec.whatwg.org/#body
    170  *
    171  * @param   Stream  body  Readable stream
    172  * @param   Object  opts  Response options
    173  * @return  Void
    174  */
    175 function Body(body) {
    176 	var _this = this;
    177 
    178 	var _ref = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
    179 	    _ref$size = _ref.size;
    180 
    181 	let size = _ref$size === undefined ? 0 : _ref$size;
    182 	var _ref$timeout = _ref.timeout;
    183 	let timeout = _ref$timeout === undefined ? 0 : _ref$timeout;
    184 
    185 	if (body == null) {
    186 		// body is undefined or null
    187 		body = null;
    188 	} else if (isURLSearchParams(body)) {
    189 		// body is a URLSearchParams
    190 		body = Buffer.from(body.toString());
    191 	} else if (isBlob(body)) ; else if (Buffer.isBuffer(body)) ; else if (Object.prototype.toString.call(body) === '[object ArrayBuffer]') {
    192 		// body is ArrayBuffer
    193 		body = Buffer.from(body);
    194 	} else if (ArrayBuffer.isView(body)) {
    195 		// body is ArrayBufferView
    196 		body = Buffer.from(body.buffer, body.byteOffset, body.byteLength);
    197 	} else if (body instanceof Stream) ; else {
    198 		// none of the above
    199 		// coerce to string then buffer
    200 		body = Buffer.from(String(body));
    201 	}
    202 	this[INTERNALS] = {
    203 		body,
    204 		disturbed: false,
    205 		error: null
    206 	};
    207 	this.size = size;
    208 	this.timeout = timeout;
    209 
    210 	if (body instanceof Stream) {
    211 		body.on('error', function (err) {
    212 			const error = err.name === 'AbortError' ? err : new FetchError(`Invalid response body while trying to fetch ${_this.url}: ${err.message}`, 'system', err);
    213 			_this[INTERNALS].error = error;
    214 		});
    215 	}
    216 }
    217 
    218 Body.prototype = {
    219 	get body() {
    220 		return this[INTERNALS].body;
    221 	},
    222 
    223 	get bodyUsed() {
    224 		return this[INTERNALS].disturbed;
    225 	},
    226 
    227 	/**
    228   * Decode response as ArrayBuffer
    229   *
    230   * @return  Promise
    231   */
    232 	arrayBuffer() {
    233 		return consumeBody.call(this).then(function (buf) {
    234 			return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
    235 		});
    236 	},
    237 
    238 	/**
    239   * Return raw response as Blob
    240   *
    241   * @return Promise
    242   */
    243 	blob() {
    244 		let ct = this.headers && this.headers.get('content-type') || '';
    245 		return consumeBody.call(this).then(function (buf) {
    246 			return Object.assign(
    247 			// Prevent copying
    248 			new Blob([], {
    249 				type: ct.toLowerCase()
    250 			}), {
    251 				[BUFFER]: buf
    252 			});
    253 		});
    254 	},
    255 
    256 	/**
    257   * Decode response as json
    258   *
    259   * @return  Promise
    260   */
    261 	json() {
    262 		var _this2 = this;
    263 
    264 		return consumeBody.call(this).then(function (buffer) {
    265 			try {
    266 				return JSON.parse(buffer.toString());
    267 			} catch (err) {
    268 				return Body.Promise.reject(new FetchError(`invalid json response body at ${_this2.url} reason: ${err.message}`, 'invalid-json'));
    269 			}
    270 		});
    271 	},
    272 
    273 	/**
    274   * Decode response as text
    275   *
    276   * @return  Promise
    277   */
    278 	text() {
    279 		return consumeBody.call(this).then(function (buffer) {
    280 			return buffer.toString();
    281 		});
    282 	},
    283 
    284 	/**
    285   * Decode response as buffer (non-spec api)
    286   *
    287   * @return  Promise
    288   */
    289 	buffer() {
    290 		return consumeBody.call(this);
    291 	},
    292 
    293 	/**
    294   * Decode response as text, while automatically detecting the encoding and
    295   * trying to decode to UTF-8 (non-spec api)
    296   *
    297   * @return  Promise
    298   */
    299 	textConverted() {
    300 		var _this3 = this;
    301 
    302 		return consumeBody.call(this).then(function (buffer) {
    303 			return convertBody(buffer, _this3.headers);
    304 		});
    305 	}
    306 };
    307 
    308 // In browsers, all properties are enumerable.
    309 Object.defineProperties(Body.prototype, {
    310 	body: { enumerable: true },
    311 	bodyUsed: { enumerable: true },
    312 	arrayBuffer: { enumerable: true },
    313 	blob: { enumerable: true },
    314 	json: { enumerable: true },
    315 	text: { enumerable: true }
    316 });
    317 
    318 Body.mixIn = function (proto) {
    319 	for (const name of Object.getOwnPropertyNames(Body.prototype)) {
    320 		// istanbul ignore else: future proof
    321 		if (!(name in proto)) {
    322 			const desc = Object.getOwnPropertyDescriptor(Body.prototype, name);
    323 			Object.defineProperty(proto, name, desc);
    324 		}
    325 	}
    326 };
    327 
    328 /**
    329  * Consume and convert an entire Body to a Buffer.
    330  *
    331  * Ref: https://fetch.spec.whatwg.org/#concept-body-consume-body
    332  *
    333  * @return  Promise
    334  */
    335 function consumeBody() {
    336 	var _this4 = this;
    337 
    338 	if (this[INTERNALS].disturbed) {
    339 		return Body.Promise.reject(new TypeError(`body used already for: ${this.url}`));
    340 	}
    341 
    342 	this[INTERNALS].disturbed = true;
    343 
    344 	if (this[INTERNALS].error) {
    345 		return Body.Promise.reject(this[INTERNALS].error);
    346 	}
    347 
    348 	let body = this.body;
    349 
    350 	// body is null
    351 	if (body === null) {
    352 		return Body.Promise.resolve(Buffer.alloc(0));
    353 	}
    354 
    355 	// body is blob
    356 	if (isBlob(body)) {
    357 		body = body.stream();
    358 	}
    359 
    360 	// body is buffer
    361 	if (Buffer.isBuffer(body)) {
    362 		return Body.Promise.resolve(body);
    363 	}
    364 
    365 	// istanbul ignore if: should never happen
    366 	if (!(body instanceof Stream)) {
    367 		return Body.Promise.resolve(Buffer.alloc(0));
    368 	}
    369 
    370 	// body is stream
    371 	// get ready to actually consume the body
    372 	let accum = [];
    373 	let accumBytes = 0;
    374 	let abort = false;
    375 
    376 	return new Body.Promise(function (resolve, reject) {
    377 		let resTimeout;
    378 
    379 		// allow timeout on slow response body
    380 		if (_this4.timeout) {
    381 			resTimeout = setTimeout(function () {
    382 				abort = true;
    383 				reject(new FetchError(`Response timeout while trying to fetch ${_this4.url} (over ${_this4.timeout}ms)`, 'body-timeout'));
    384 			}, _this4.timeout);
    385 		}
    386 
    387 		// handle stream errors
    388 		body.on('error', function (err) {
    389 			if (err.name === 'AbortError') {
    390 				// if the request was aborted, reject with this Error
    391 				abort = true;
    392 				reject(err);
    393 			} else {
    394 				// other errors, such as incorrect content-encoding
    395 				reject(new FetchError(`Invalid response body while trying to fetch ${_this4.url}: ${err.message}`, 'system', err));
    396 			}
    397 		});
    398 
    399 		body.on('data', function (chunk) {
    400 			if (abort || chunk === null) {
    401 				return;
    402 			}
    403 
    404 			if (_this4.size && accumBytes + chunk.length > _this4.size) {
    405 				abort = true;
    406 				reject(new FetchError(`content size at ${_this4.url} over limit: ${_this4.size}`, 'max-size'));
    407 				return;
    408 			}
    409 
    410 			accumBytes += chunk.length;
    411 			accum.push(chunk);
    412 		});
    413 
    414 		body.on('end', function () {
    415 			if (abort) {
    416 				return;
    417 			}
    418 
    419 			clearTimeout(resTimeout);
    420 
    421 			try {
    422 				resolve(Buffer.concat(accum, accumBytes));
    423 			} catch (err) {
    424 				// handle streams that have accumulated too much data (issue #414)
    425 				reject(new FetchError(`Could not create Buffer from response body for ${_this4.url}: ${err.message}`, 'system', err));
    426 			}
    427 		});
    428 	});
    429 }
    430 
    431 /**
    432  * Detect buffer encoding and convert to target encoding
    433  * ref: http://www.w3.org/TR/2011/WD-html5-20110113/parsing.html#determining-the-character-encoding
    434  *
    435  * @param   Buffer  buffer    Incoming buffer
    436  * @param   String  encoding  Target encoding
    437  * @return  String
    438  */
    439 function convertBody(buffer, headers) {
    440 	if (typeof convert !== 'function') {
    441 		throw new Error('The package `encoding` must be installed to use the textConverted() function');
    442 	}
    443 
    444 	const ct = headers.get('content-type');
    445 	let charset = 'utf-8';
    446 	let res, str;
    447 
    448 	// header
    449 	if (ct) {
    450 		res = /charset=([^;]*)/i.exec(ct);
    451 	}
    452 
    453 	// no charset in content type, peek at response body for at most 1024 bytes
    454 	str = buffer.slice(0, 1024).toString();
    455 
    456 	// html5
    457 	if (!res && str) {
    458 		res = /<meta.+?charset=(['"])(.+?)\1/i.exec(str);
    459 	}
    460 
    461 	// html4
    462 	if (!res && str) {
    463 		res = /<meta[\s]+?http-equiv=(['"])content-type\1[\s]+?content=(['"])(.+?)\2/i.exec(str);
    464 
    465 		if (res) {
    466 			res = /charset=(.*)/i.exec(res.pop());
    467 		}
    468 	}
    469 
    470 	// xml
    471 	if (!res && str) {
    472 		res = /<\?xml.+?encoding=(['"])(.+?)\1/i.exec(str);
    473 	}
    474 
    475 	// found charset
    476 	if (res) {
    477 		charset = res.pop();
    478 
    479 		// prevent decode issues when sites use incorrect encoding
    480 		// ref: https://hsivonen.fi/encoding-menu/
    481 		if (charset === 'gb2312' || charset === 'gbk') {
    482 			charset = 'gb18030';
    483 		}
    484 	}
    485 
    486 	// turn raw buffers into a single utf-8 buffer
    487 	return convert(buffer, 'UTF-8', charset).toString();
    488 }
    489 
    490 /**
    491  * Detect a URLSearchParams object
    492  * ref: https://github.com/bitinn/node-fetch/issues/296#issuecomment-307598143
    493  *
    494  * @param   Object  obj     Object to detect by type or brand
    495  * @return  String
    496  */
    497 function isURLSearchParams(obj) {
    498 	// Duck-typing as a necessary condition.
    499 	if (typeof obj !== 'object' || typeof obj.append !== 'function' || typeof obj.delete !== 'function' || typeof obj.get !== 'function' || typeof obj.getAll !== 'function' || typeof obj.has !== 'function' || typeof obj.set !== 'function') {
    500 		return false;
    501 	}
    502 
    503 	// Brand-checking and more duck-typing as optional condition.
    504 	return obj.constructor.name === 'URLSearchParams' || Object.prototype.toString.call(obj) === '[object URLSearchParams]' || typeof obj.sort === 'function';
    505 }
    506 
    507 /**
    508  * Check if `obj` is a W3C `Blob` object (which `File` inherits from)
    509  * @param  {*} obj
    510  * @return {boolean}
    511  */
    512 function isBlob(obj) {
    513 	return typeof obj === 'object' && typeof obj.arrayBuffer === 'function' && typeof obj.type === 'string' && typeof obj.stream === 'function' && typeof obj.constructor === 'function' && typeof obj.constructor.name === 'string' && /^(Blob|File)$/.test(obj.constructor.name) && /^(Blob|File)$/.test(obj[Symbol.toStringTag]);
    514 }
    515 
    516 /**
    517  * Clone body given Res/Req instance
    518  *
    519  * @param   Mixed  instance  Response or Request instance
    520  * @return  Mixed
    521  */
    522 function clone(instance) {
    523 	let p1, p2;
    524 	let body = instance.body;
    525 
    526 	// don't allow cloning a used body
    527 	if (instance.bodyUsed) {
    528 		throw new Error('cannot clone body after it is used');
    529 	}
    530 
    531 	// check that body is a stream and not form-data object
    532 	// note: we can't clone the form-data object without having it as a dependency
    533 	if (body instanceof Stream && typeof body.getBoundary !== 'function') {
    534 		// tee instance body
    535 		p1 = new PassThrough();
    536 		p2 = new PassThrough();
    537 		body.pipe(p1);
    538 		body.pipe(p2);
    539 		// set instance body to teed body and return the other teed body
    540 		instance[INTERNALS].body = p1;
    541 		body = p2;
    542 	}
    543 
    544 	return body;
    545 }
    546 
    547 /**
    548  * Performs the operation "extract a `Content-Type` value from |object|" as
    549  * specified in the specification:
    550  * https://fetch.spec.whatwg.org/#concept-bodyinit-extract
    551  *
    552  * This function assumes that instance.body is present.
    553  *
    554  * @param   Mixed  instance  Any options.body input
    555  */
    556 function extractContentType(body) {
    557 	if (body === null) {
    558 		// body is null
    559 		return null;
    560 	} else if (typeof body === 'string') {
    561 		// body is string
    562 		return 'text/plain;charset=UTF-8';
    563 	} else if (isURLSearchParams(body)) {
    564 		// body is a URLSearchParams
    565 		return 'application/x-www-form-urlencoded;charset=UTF-8';
    566 	} else if (isBlob(body)) {
    567 		// body is blob
    568 		return body.type || null;
    569 	} else if (Buffer.isBuffer(body)) {
    570 		// body is buffer
    571 		return null;
    572 	} else if (Object.prototype.toString.call(body) === '[object ArrayBuffer]') {
    573 		// body is ArrayBuffer
    574 		return null;
    575 	} else if (ArrayBuffer.isView(body)) {
    576 		// body is ArrayBufferView
    577 		return null;
    578 	} else if (typeof body.getBoundary === 'function') {
    579 		// detect form data input from form-data module
    580 		return `multipart/form-data;boundary=${body.getBoundary()}`;
    581 	} else if (body instanceof Stream) {
    582 		// body is stream
    583 		// can't really do much about this
    584 		return null;
    585 	} else {
    586 		// Body constructor defaults other things to string
    587 		return 'text/plain;charset=UTF-8';
    588 	}
    589 }
    590 
    591 /**
    592  * The Fetch Standard treats this as if "total bytes" is a property on the body.
    593  * For us, we have to explicitly get it with a function.
    594  *
    595  * ref: https://fetch.spec.whatwg.org/#concept-body-total-bytes
    596  *
    597  * @param   Body    instance   Instance of Body
    598  * @return  Number?            Number of bytes, or null if not possible
    599  */
    600 function getTotalBytes(instance) {
    601 	const body = instance.body;
    602 
    603 
    604 	if (body === null) {
    605 		// body is null
    606 		return 0;
    607 	} else if (isBlob(body)) {
    608 		return body.size;
    609 	} else if (Buffer.isBuffer(body)) {
    610 		// body is buffer
    611 		return body.length;
    612 	} else if (body && typeof body.getLengthSync === 'function') {
    613 		// detect form data input from form-data module
    614 		if (body._lengthRetrievers && body._lengthRetrievers.length == 0 || // 1.x
    615 		body.hasKnownLength && body.hasKnownLength()) {
    616 			// 2.x
    617 			return body.getLengthSync();
    618 		}
    619 		return null;
    620 	} else {
    621 		// body is stream
    622 		return null;
    623 	}
    624 }
    625 
    626 /**
    627  * Write a Body to a Node.js WritableStream (e.g. http.Request) object.
    628  *
    629  * @param   Body    instance   Instance of Body
    630  * @return  Void
    631  */
    632 function writeToStream(dest, instance) {
    633 	const body = instance.body;
    634 
    635 
    636 	if (body === null) {
    637 		// body is null
    638 		dest.end();
    639 	} else if (isBlob(body)) {
    640 		body.stream().pipe(dest);
    641 	} else if (Buffer.isBuffer(body)) {
    642 		// body is buffer
    643 		dest.write(body);
    644 		dest.end();
    645 	} else {
    646 		// body is stream
    647 		body.pipe(dest);
    648 	}
    649 }
    650 
    651 // expose Promise
    652 Body.Promise = global.Promise;
    653 
    654 /**
    655  * headers.js
    656  *
    657  * Headers class offers convenient helpers
    658  */
    659 
    660 const invalidTokenRegex = /[^\^_`a-zA-Z\-0-9!#$%&'*+.|~]/;
    661 const invalidHeaderCharRegex = /[^\t\x20-\x7e\x80-\xff]/;
    662 
    663 function validateName(name) {
    664 	name = `${name}`;
    665 	if (invalidTokenRegex.test(name) || name === '') {
    666 		throw new TypeError(`${name} is not a legal HTTP header name`);
    667 	}
    668 }
    669 
    670 function validateValue(value) {
    671 	value = `${value}`;
    672 	if (invalidHeaderCharRegex.test(value)) {
    673 		throw new TypeError(`${value} is not a legal HTTP header value`);
    674 	}
    675 }
    676 
    677 /**
    678  * Find the key in the map object given a header name.
    679  *
    680  * Returns undefined if not found.
    681  *
    682  * @param   String  name  Header name
    683  * @return  String|Undefined
    684  */
    685 function find(map, name) {
    686 	name = name.toLowerCase();
    687 	for (const key in map) {
    688 		if (key.toLowerCase() === name) {
    689 			return key;
    690 		}
    691 	}
    692 	return undefined;
    693 }
    694 
    695 const MAP = Symbol('map');
    696 class Headers {
    697 	/**
    698   * Headers class
    699   *
    700   * @param   Object  headers  Response headers
    701   * @return  Void
    702   */
    703 	constructor() {
    704 		let init = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : undefined;
    705 
    706 		this[MAP] = Object.create(null);
    707 
    708 		if (init instanceof Headers) {
    709 			const rawHeaders = init.raw();
    710 			const headerNames = Object.keys(rawHeaders);
    711 
    712 			for (const headerName of headerNames) {
    713 				for (const value of rawHeaders[headerName]) {
    714 					this.append(headerName, value);
    715 				}
    716 			}
    717 
    718 			return;
    719 		}
    720 
    721 		// We don't worry about converting prop to ByteString here as append()
    722 		// will handle it.
    723 		if (init == null) ; else if (typeof init === 'object') {
    724 			const method = init[Symbol.iterator];
    725 			if (method != null) {
    726 				if (typeof method !== 'function') {
    727 					throw new TypeError('Header pairs must be iterable');
    728 				}
    729 
    730 				// sequence<sequence<ByteString>>
    731 				// Note: per spec we have to first exhaust the lists then process them
    732 				const pairs = [];
    733 				for (const pair of init) {
    734 					if (typeof pair !== 'object' || typeof pair[Symbol.iterator] !== 'function') {
    735 						throw new TypeError('Each header pair must be iterable');
    736 					}
    737 					pairs.push(Array.from(pair));
    738 				}
    739 
    740 				for (const pair of pairs) {
    741 					if (pair.length !== 2) {
    742 						throw new TypeError('Each header pair must be a name/value tuple');
    743 					}
    744 					this.append(pair[0], pair[1]);
    745 				}
    746 			} else {
    747 				// record<ByteString, ByteString>
    748 				for (const key of Object.keys(init)) {
    749 					const value = init[key];
    750 					this.append(key, value);
    751 				}
    752 			}
    753 		} else {
    754 			throw new TypeError('Provided initializer must be an object');
    755 		}
    756 	}
    757 
    758 	/**
    759   * Return combined header value given name
    760   *
    761   * @param   String  name  Header name
    762   * @return  Mixed
    763   */
    764 	get(name) {
    765 		name = `${name}`;
    766 		validateName(name);
    767 		const key = find(this[MAP], name);
    768 		if (key === undefined) {
    769 			return null;
    770 		}
    771 
    772 		return this[MAP][key].join(', ');
    773 	}
    774 
    775 	/**
    776   * Iterate over all headers
    777   *
    778   * @param   Function  callback  Executed for each item with parameters (value, name, thisArg)
    779   * @param   Boolean   thisArg   `this` context for callback function
    780   * @return  Void
    781   */
    782 	forEach(callback) {
    783 		let thisArg = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : undefined;
    784 
    785 		let pairs = getHeaders(this);
    786 		let i = 0;
    787 		while (i < pairs.length) {
    788 			var _pairs$i = pairs[i];
    789 			const name = _pairs$i[0],
    790 			      value = _pairs$i[1];
    791 
    792 			callback.call(thisArg, value, name, this);
    793 			pairs = getHeaders(this);
    794 			i++;
    795 		}
    796 	}
    797 
    798 	/**
    799   * Overwrite header values given name
    800   *
    801   * @param   String  name   Header name
    802   * @param   String  value  Header value
    803   * @return  Void
    804   */
    805 	set(name, value) {
    806 		name = `${name}`;
    807 		value = `${value}`;
    808 		validateName(name);
    809 		validateValue(value);
    810 		const key = find(this[MAP], name);
    811 		this[MAP][key !== undefined ? key : name] = [value];
    812 	}
    813 
    814 	/**
    815   * Append a value onto existing header
    816   *
    817   * @param   String  name   Header name
    818   * @param   String  value  Header value
    819   * @return  Void
    820   */
    821 	append(name, value) {
    822 		name = `${name}`;
    823 		value = `${value}`;
    824 		validateName(name);
    825 		validateValue(value);
    826 		const key = find(this[MAP], name);
    827 		if (key !== undefined) {
    828 			this[MAP][key].push(value);
    829 		} else {
    830 			this[MAP][name] = [value];
    831 		}
    832 	}
    833 
    834 	/**
    835   * Check for header name existence
    836   *
    837   * @param   String   name  Header name
    838   * @return  Boolean
    839   */
    840 	has(name) {
    841 		name = `${name}`;
    842 		validateName(name);
    843 		return find(this[MAP], name) !== undefined;
    844 	}
    845 
    846 	/**
    847   * Delete all header values given name
    848   *
    849   * @param   String  name  Header name
    850   * @return  Void
    851   */
    852 	delete(name) {
    853 		name = `${name}`;
    854 		validateName(name);
    855 		const key = find(this[MAP], name);
    856 		if (key !== undefined) {
    857 			delete this[MAP][key];
    858 		}
    859 	}
    860 
    861 	/**
    862   * Return raw headers (non-spec api)
    863   *
    864   * @return  Object
    865   */
    866 	raw() {
    867 		return this[MAP];
    868 	}
    869 
    870 	/**
    871   * Get an iterator on keys.
    872   *
    873   * @return  Iterator
    874   */
    875 	keys() {
    876 		return createHeadersIterator(this, 'key');
    877 	}
    878 
    879 	/**
    880   * Get an iterator on values.
    881   *
    882   * @return  Iterator
    883   */
    884 	values() {
    885 		return createHeadersIterator(this, 'value');
    886 	}
    887 
    888 	/**
    889   * Get an iterator on entries.
    890   *
    891   * This is the default iterator of the Headers object.
    892   *
    893   * @return  Iterator
    894   */
    895 	[Symbol.iterator]() {
    896 		return createHeadersIterator(this, 'key+value');
    897 	}
    898 }
    899 Headers.prototype.entries = Headers.prototype[Symbol.iterator];
    900 
    901 Object.defineProperty(Headers.prototype, Symbol.toStringTag, {
    902 	value: 'Headers',
    903 	writable: false,
    904 	enumerable: false,
    905 	configurable: true
    906 });
    907 
    908 Object.defineProperties(Headers.prototype, {
    909 	get: { enumerable: true },
    910 	forEach: { enumerable: true },
    911 	set: { enumerable: true },
    912 	append: { enumerable: true },
    913 	has: { enumerable: true },
    914 	delete: { enumerable: true },
    915 	keys: { enumerable: true },
    916 	values: { enumerable: true },
    917 	entries: { enumerable: true }
    918 });
    919 
    920 function getHeaders(headers) {
    921 	let kind = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'key+value';
    922 
    923 	const keys = Object.keys(headers[MAP]).sort();
    924 	return keys.map(kind === 'key' ? function (k) {
    925 		return k.toLowerCase();
    926 	} : kind === 'value' ? function (k) {
    927 		return headers[MAP][k].join(', ');
    928 	} : function (k) {
    929 		return [k.toLowerCase(), headers[MAP][k].join(', ')];
    930 	});
    931 }
    932 
    933 const INTERNAL = Symbol('internal');
    934 
    935 function createHeadersIterator(target, kind) {
    936 	const iterator = Object.create(HeadersIteratorPrototype);
    937 	iterator[INTERNAL] = {
    938 		target,
    939 		kind,
    940 		index: 0
    941 	};
    942 	return iterator;
    943 }
    944 
    945 const HeadersIteratorPrototype = Object.setPrototypeOf({
    946 	next() {
    947 		// istanbul ignore if
    948 		if (!this || Object.getPrototypeOf(this) !== HeadersIteratorPrototype) {
    949 			throw new TypeError('Value of `this` is not a HeadersIterator');
    950 		}
    951 
    952 		var _INTERNAL = this[INTERNAL];
    953 		const target = _INTERNAL.target,
    954 		      kind = _INTERNAL.kind,
    955 		      index = _INTERNAL.index;
    956 
    957 		const values = getHeaders(target, kind);
    958 		const len = values.length;
    959 		if (index >= len) {
    960 			return {
    961 				value: undefined,
    962 				done: true
    963 			};
    964 		}
    965 
    966 		this[INTERNAL].index = index + 1;
    967 
    968 		return {
    969 			value: values[index],
    970 			done: false
    971 		};
    972 	}
    973 }, Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]())));
    974 
    975 Object.defineProperty(HeadersIteratorPrototype, Symbol.toStringTag, {
    976 	value: 'HeadersIterator',
    977 	writable: false,
    978 	enumerable: false,
    979 	configurable: true
    980 });
    981 
    982 /**
    983  * Export the Headers object in a form that Node.js can consume.
    984  *
    985  * @param   Headers  headers
    986  * @return  Object
    987  */
    988 function exportNodeCompatibleHeaders(headers) {
    989 	const obj = Object.assign({ __proto__: null }, headers[MAP]);
    990 
    991 	// http.request() only supports string as Host header. This hack makes
    992 	// specifying custom Host header possible.
    993 	const hostHeaderKey = find(headers[MAP], 'Host');
    994 	if (hostHeaderKey !== undefined) {
    995 		obj[hostHeaderKey] = obj[hostHeaderKey][0];
    996 	}
    997 
    998 	return obj;
    999 }
   1000 
   1001 /**
   1002  * Create a Headers object from an object of headers, ignoring those that do
   1003  * not conform to HTTP grammar productions.
   1004  *
   1005  * @param   Object  obj  Object of headers
   1006  * @return  Headers
   1007  */
   1008 function createHeadersLenient(obj) {
   1009 	const headers = new Headers();
   1010 	for (const name of Object.keys(obj)) {
   1011 		if (invalidTokenRegex.test(name)) {
   1012 			continue;
   1013 		}
   1014 		if (Array.isArray(obj[name])) {
   1015 			for (const val of obj[name]) {
   1016 				if (invalidHeaderCharRegex.test(val)) {
   1017 					continue;
   1018 				}
   1019 				if (headers[MAP][name] === undefined) {
   1020 					headers[MAP][name] = [val];
   1021 				} else {
   1022 					headers[MAP][name].push(val);
   1023 				}
   1024 			}
   1025 		} else if (!invalidHeaderCharRegex.test(obj[name])) {
   1026 			headers[MAP][name] = [obj[name]];
   1027 		}
   1028 	}
   1029 	return headers;
   1030 }
   1031 
   1032 const INTERNALS$1 = Symbol('Response internals');
   1033 
   1034 // fix an issue where "STATUS_CODES" aren't a named export for node <10
   1035 const STATUS_CODES = http.STATUS_CODES;
   1036 
   1037 /**
   1038  * Response class
   1039  *
   1040  * @param   Stream  body  Readable stream
   1041  * @param   Object  opts  Response options
   1042  * @return  Void
   1043  */
   1044 class Response {
   1045 	constructor() {
   1046 		let body = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : null;
   1047 		let opts = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
   1048 
   1049 		Body.call(this, body, opts);
   1050 
   1051 		const status = opts.status || 200;
   1052 		const headers = new Headers(opts.headers);
   1053 
   1054 		if (body != null && !headers.has('Content-Type')) {
   1055 			const contentType = extractContentType(body);
   1056 			if (contentType) {
   1057 				headers.append('Content-Type', contentType);
   1058 			}
   1059 		}
   1060 
   1061 		this[INTERNALS$1] = {
   1062 			url: opts.url,
   1063 			status,
   1064 			statusText: opts.statusText || STATUS_CODES[status],
   1065 			headers,
   1066 			counter: opts.counter
   1067 		};
   1068 	}
   1069 
   1070 	get url() {
   1071 		return this[INTERNALS$1].url || '';
   1072 	}
   1073 
   1074 	get status() {
   1075 		return this[INTERNALS$1].status;
   1076 	}
   1077 
   1078 	/**
   1079   * Convenience property representing if the request ended normally
   1080   */
   1081 	get ok() {
   1082 		return this[INTERNALS$1].status >= 200 && this[INTERNALS$1].status < 300;
   1083 	}
   1084 
   1085 	get redirected() {
   1086 		return this[INTERNALS$1].counter > 0;
   1087 	}
   1088 
   1089 	get statusText() {
   1090 		return this[INTERNALS$1].statusText;
   1091 	}
   1092 
   1093 	get headers() {
   1094 		return this[INTERNALS$1].headers;
   1095 	}
   1096 
   1097 	/**
   1098   * Clone this response
   1099   *
   1100   * @return  Response
   1101   */
   1102 	clone() {
   1103 		return new Response(clone(this), {
   1104 			url: this.url,
   1105 			status: this.status,
   1106 			statusText: this.statusText,
   1107 			headers: this.headers,
   1108 			ok: this.ok,
   1109 			redirected: this.redirected
   1110 		});
   1111 	}
   1112 }
   1113 
   1114 Body.mixIn(Response.prototype);
   1115 
   1116 Object.defineProperties(Response.prototype, {
   1117 	url: { enumerable: true },
   1118 	status: { enumerable: true },
   1119 	ok: { enumerable: true },
   1120 	redirected: { enumerable: true },
   1121 	statusText: { enumerable: true },
   1122 	headers: { enumerable: true },
   1123 	clone: { enumerable: true }
   1124 });
   1125 
   1126 Object.defineProperty(Response.prototype, Symbol.toStringTag, {
   1127 	value: 'Response',
   1128 	writable: false,
   1129 	enumerable: false,
   1130 	configurable: true
   1131 });
   1132 
   1133 const INTERNALS$2 = Symbol('Request internals');
   1134 
   1135 // fix an issue where "format", "parse" aren't a named export for node <10
   1136 const parse_url = Url.parse;
   1137 const format_url = Url.format;
   1138 
   1139 const streamDestructionSupported = 'destroy' in Stream.Readable.prototype;
   1140 
   1141 /**
   1142  * Check if a value is an instance of Request.
   1143  *
   1144  * @param   Mixed   input
   1145  * @return  Boolean
   1146  */
   1147 function isRequest(input) {
   1148 	return typeof input === 'object' && typeof input[INTERNALS$2] === 'object';
   1149 }
   1150 
   1151 function isAbortSignal(signal) {
   1152 	const proto = signal && typeof signal === 'object' && Object.getPrototypeOf(signal);
   1153 	return !!(proto && proto.constructor.name === 'AbortSignal');
   1154 }
   1155 
   1156 /**
   1157  * Request class
   1158  *
   1159  * @param   Mixed   input  Url or Request instance
   1160  * @param   Object  init   Custom options
   1161  * @return  Void
   1162  */
   1163 class Request {
   1164 	constructor(input) {
   1165 		let init = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
   1166 
   1167 		let parsedURL;
   1168 
   1169 		// normalize input
   1170 		if (!isRequest(input)) {
   1171 			if (input && input.href) {
   1172 				// in order to support Node.js' Url objects; though WHATWG's URL objects
   1173 				// will fall into this branch also (since their `toString()` will return
   1174 				// `href` property anyway)
   1175 				parsedURL = parse_url(input.href);
   1176 			} else {
   1177 				// coerce input to a string before attempting to parse
   1178 				parsedURL = parse_url(`${input}`);
   1179 			}
   1180 			input = {};
   1181 		} else {
   1182 			parsedURL = parse_url(input.url);
   1183 		}
   1184 
   1185 		let method = init.method || input.method || 'GET';
   1186 		method = method.toUpperCase();
   1187 
   1188 		if ((init.body != null || isRequest(input) && input.body !== null) && (method === 'GET' || method === 'HEAD')) {
   1189 			throw new TypeError('Request with GET/HEAD method cannot have body');
   1190 		}
   1191 
   1192 		let inputBody = init.body != null ? init.body : isRequest(input) && input.body !== null ? clone(input) : null;
   1193 
   1194 		Body.call(this, inputBody, {
   1195 			timeout: init.timeout || input.timeout || 0,
   1196 			size: init.size || input.size || 0
   1197 		});
   1198 
   1199 		const headers = new Headers(init.headers || input.headers || {});
   1200 
   1201 		if (inputBody != null && !headers.has('Content-Type')) {
   1202 			const contentType = extractContentType(inputBody);
   1203 			if (contentType) {
   1204 				headers.append('Content-Type', contentType);
   1205 			}
   1206 		}
   1207 
   1208 		let signal = isRequest(input) ? input.signal : null;
   1209 		if ('signal' in init) signal = init.signal;
   1210 
   1211 		if (signal != null && !isAbortSignal(signal)) {
   1212 			throw new TypeError('Expected signal to be an instanceof AbortSignal');
   1213 		}
   1214 
   1215 		this[INTERNALS$2] = {
   1216 			method,
   1217 			redirect: init.redirect || input.redirect || 'follow',
   1218 			headers,
   1219 			parsedURL,
   1220 			signal
   1221 		};
   1222 
   1223 		// node-fetch-only options
   1224 		this.follow = init.follow !== undefined ? init.follow : input.follow !== undefined ? input.follow : 20;
   1225 		this.compress = init.compress !== undefined ? init.compress : input.compress !== undefined ? input.compress : true;
   1226 		this.counter = init.counter || input.counter || 0;
   1227 		this.agent = init.agent || input.agent;
   1228 	}
   1229 
   1230 	get method() {
   1231 		return this[INTERNALS$2].method;
   1232 	}
   1233 
   1234 	get url() {
   1235 		return format_url(this[INTERNALS$2].parsedURL);
   1236 	}
   1237 
   1238 	get headers() {
   1239 		return this[INTERNALS$2].headers;
   1240 	}
   1241 
   1242 	get redirect() {
   1243 		return this[INTERNALS$2].redirect;
   1244 	}
   1245 
   1246 	get signal() {
   1247 		return this[INTERNALS$2].signal;
   1248 	}
   1249 
   1250 	/**
   1251   * Clone this request
   1252   *
   1253   * @return  Request
   1254   */
   1255 	clone() {
   1256 		return new Request(this);
   1257 	}
   1258 }
   1259 
   1260 Body.mixIn(Request.prototype);
   1261 
   1262 Object.defineProperty(Request.prototype, Symbol.toStringTag, {
   1263 	value: 'Request',
   1264 	writable: false,
   1265 	enumerable: false,
   1266 	configurable: true
   1267 });
   1268 
   1269 Object.defineProperties(Request.prototype, {
   1270 	method: { enumerable: true },
   1271 	url: { enumerable: true },
   1272 	headers: { enumerable: true },
   1273 	redirect: { enumerable: true },
   1274 	clone: { enumerable: true },
   1275 	signal: { enumerable: true }
   1276 });
   1277 
   1278 /**
   1279  * Convert a Request to Node.js http request options.
   1280  *
   1281  * @param   Request  A Request instance
   1282  * @return  Object   The options object to be passed to http.request
   1283  */
   1284 function getNodeRequestOptions(request) {
   1285 	const parsedURL = request[INTERNALS$2].parsedURL;
   1286 	const headers = new Headers(request[INTERNALS$2].headers);
   1287 
   1288 	// fetch step 1.3
   1289 	if (!headers.has('Accept')) {
   1290 		headers.set('Accept', '*/*');
   1291 	}
   1292 
   1293 	// Basic fetch
   1294 	if (!parsedURL.protocol || !parsedURL.hostname) {
   1295 		throw new TypeError('Only absolute URLs are supported');
   1296 	}
   1297 
   1298 	if (!/^https?:$/.test(parsedURL.protocol)) {
   1299 		throw new TypeError('Only HTTP(S) protocols are supported');
   1300 	}
   1301 
   1302 	if (request.signal && request.body instanceof Stream.Readable && !streamDestructionSupported) {
   1303 		throw new Error('Cancellation of streamed requests with AbortSignal is not supported in node < 8');
   1304 	}
   1305 
   1306 	// HTTP-network-or-cache fetch steps 2.4-2.7
   1307 	let contentLengthValue = null;
   1308 	if (request.body == null && /^(POST|PUT)$/i.test(request.method)) {
   1309 		contentLengthValue = '0';
   1310 	}
   1311 	if (request.body != null) {
   1312 		const totalBytes = getTotalBytes(request);
   1313 		if (typeof totalBytes === 'number') {
   1314 			contentLengthValue = String(totalBytes);
   1315 		}
   1316 	}
   1317 	if (contentLengthValue) {
   1318 		headers.set('Content-Length', contentLengthValue);
   1319 	}
   1320 
   1321 	// HTTP-network-or-cache fetch step 2.11
   1322 	if (!headers.has('User-Agent')) {
   1323 		headers.set('User-Agent', 'node-fetch/1.0 (+https://github.com/bitinn/node-fetch)');
   1324 	}
   1325 
   1326 	// HTTP-network-or-cache fetch step 2.15
   1327 	if (request.compress && !headers.has('Accept-Encoding')) {
   1328 		headers.set('Accept-Encoding', 'gzip,deflate');
   1329 	}
   1330 
   1331 	let agent = request.agent;
   1332 	if (typeof agent === 'function') {
   1333 		agent = agent(parsedURL);
   1334 	}
   1335 
   1336 	if (!headers.has('Connection') && !agent) {
   1337 		headers.set('Connection', 'close');
   1338 	}
   1339 
   1340 	// HTTP-network fetch step 4.2
   1341 	// chunked encoding is handled by Node.js
   1342 
   1343 	return Object.assign({}, parsedURL, {
   1344 		method: request.method,
   1345 		headers: exportNodeCompatibleHeaders(headers),
   1346 		agent
   1347 	});
   1348 }
   1349 
   1350 /**
   1351  * abort-error.js
   1352  *
   1353  * AbortError interface for cancelled requests
   1354  */
   1355 
   1356 /**
   1357  * Create AbortError instance
   1358  *
   1359  * @param   String      message      Error message for human
   1360  * @return  AbortError
   1361  */
   1362 function AbortError(message) {
   1363   Error.call(this, message);
   1364 
   1365   this.type = 'aborted';
   1366   this.message = message;
   1367 
   1368   // hide custom error implementation details from end-users
   1369   Error.captureStackTrace(this, this.constructor);
   1370 }
   1371 
   1372 AbortError.prototype = Object.create(Error.prototype);
   1373 AbortError.prototype.constructor = AbortError;
   1374 AbortError.prototype.name = 'AbortError';
   1375 
   1376 // fix an issue where "PassThrough", "resolve" aren't a named export for node <10
   1377 const PassThrough$1 = Stream.PassThrough;
   1378 const resolve_url = Url.resolve;
   1379 
   1380 /**
   1381  * Fetch function
   1382  *
   1383  * @param   Mixed    url   Absolute url or Request instance
   1384  * @param   Object   opts  Fetch options
   1385  * @return  Promise
   1386  */
   1387 function fetch(url, opts) {
   1388 
   1389 	// allow custom promise
   1390 	if (!fetch.Promise) {
   1391 		throw new Error('native promise missing, set fetch.Promise to your favorite alternative');
   1392 	}
   1393 
   1394 	Body.Promise = fetch.Promise;
   1395 
   1396 	// wrap http.request into fetch
   1397 	return new fetch.Promise(function (resolve, reject) {
   1398 		// build request object
   1399 		const request = new Request(url, opts);
   1400 		const options = getNodeRequestOptions(request);
   1401 
   1402 		const send = (options.protocol === 'https:' ? https : http).request;
   1403 		const signal = request.signal;
   1404 
   1405 		let response = null;
   1406 
   1407 		const abort = function abort() {
   1408 			let error = new AbortError('The user aborted a request.');
   1409 			reject(error);
   1410 			if (request.body && request.body instanceof Stream.Readable) {
   1411 				request.body.destroy(error);
   1412 			}
   1413 			if (!response || !response.body) return;
   1414 			response.body.emit('error', error);
   1415 		};
   1416 
   1417 		if (signal && signal.aborted) {
   1418 			abort();
   1419 			return;
   1420 		}
   1421 
   1422 		const abortAndFinalize = function abortAndFinalize() {
   1423 			abort();
   1424 			finalize();
   1425 		};
   1426 
   1427 		// send request
   1428 		const req = send(options);
   1429 		let reqTimeout;
   1430 
   1431 		if (signal) {
   1432 			signal.addEventListener('abort', abortAndFinalize);
   1433 		}
   1434 
   1435 		function finalize() {
   1436 			req.abort();
   1437 			if (signal) signal.removeEventListener('abort', abortAndFinalize);
   1438 			clearTimeout(reqTimeout);
   1439 		}
   1440 
   1441 		if (request.timeout) {
   1442 			req.once('socket', function (socket) {
   1443 				reqTimeout = setTimeout(function () {
   1444 					reject(new FetchError(`network timeout at: ${request.url}`, 'request-timeout'));
   1445 					finalize();
   1446 				}, request.timeout);
   1447 			});
   1448 		}
   1449 
   1450 		req.on('error', function (err) {
   1451 			reject(new FetchError(`request to ${request.url} failed, reason: ${err.message}`, 'system', err));
   1452 			finalize();
   1453 		});
   1454 
   1455 		req.on('response', function (res) {
   1456 			clearTimeout(reqTimeout);
   1457 
   1458 			const headers = createHeadersLenient(res.headers);
   1459 
   1460 			// HTTP fetch step 5
   1461 			if (fetch.isRedirect(res.statusCode)) {
   1462 				// HTTP fetch step 5.2
   1463 				const location = headers.get('Location');
   1464 
   1465 				// HTTP fetch step 5.3
   1466 				const locationURL = location === null ? null : resolve_url(request.url, location);
   1467 
   1468 				// HTTP fetch step 5.5
   1469 				switch (request.redirect) {
   1470 					case 'error':
   1471 						reject(new FetchError(`redirect mode is set to error: ${request.url}`, 'no-redirect'));
   1472 						finalize();
   1473 						return;
   1474 					case 'manual':
   1475 						// node-fetch-specific step: make manual redirect a bit easier to use by setting the Location header value to the resolved URL.
   1476 						if (locationURL !== null) {
   1477 							// handle corrupted header
   1478 							try {
   1479 								headers.set('Location', locationURL);
   1480 							} catch (err) {
   1481 								// istanbul ignore next: nodejs server prevent invalid response headers, we can't test this through normal request
   1482 								reject(err);
   1483 							}
   1484 						}
   1485 						break;
   1486 					case 'follow':
   1487 						// HTTP-redirect fetch step 2
   1488 						if (locationURL === null) {
   1489 							break;
   1490 						}
   1491 
   1492 						// HTTP-redirect fetch step 5
   1493 						if (request.counter >= request.follow) {
   1494 							reject(new FetchError(`maximum redirect reached at: ${request.url}`, 'max-redirect'));
   1495 							finalize();
   1496 							return;
   1497 						}
   1498 
   1499 						// HTTP-redirect fetch step 6 (counter increment)
   1500 						// Create a new Request object.
   1501 						const requestOpts = {
   1502 							headers: new Headers(request.headers),
   1503 							follow: request.follow,
   1504 							counter: request.counter + 1,
   1505 							agent: request.agent,
   1506 							compress: request.compress,
   1507 							method: request.method,
   1508 							body: request.body,
   1509 							signal: request.signal,
   1510 							timeout: request.timeout
   1511 						};
   1512 
   1513 						// HTTP-redirect fetch step 9
   1514 						if (res.statusCode !== 303 && request.body && getTotalBytes(request) === null) {
   1515 							reject(new FetchError('Cannot follow redirect with body being a readable stream', 'unsupported-redirect'));
   1516 							finalize();
   1517 							return;
   1518 						}
   1519 
   1520 						// HTTP-redirect fetch step 11
   1521 						if (res.statusCode === 303 || (res.statusCode === 301 || res.statusCode === 302) && request.method === 'POST') {
   1522 							requestOpts.method = 'GET';
   1523 							requestOpts.body = undefined;
   1524 							requestOpts.headers.delete('content-length');
   1525 						}
   1526 
   1527 						// HTTP-redirect fetch step 15
   1528 						resolve(fetch(new Request(locationURL, requestOpts)));
   1529 						finalize();
   1530 						return;
   1531 				}
   1532 			}
   1533 
   1534 			// prepare response
   1535 			res.once('end', function () {
   1536 				if (signal) signal.removeEventListener('abort', abortAndFinalize);
   1537 			});
   1538 			let body = res.pipe(new PassThrough$1());
   1539 
   1540 			const response_options = {
   1541 				url: request.url,
   1542 				status: res.statusCode,
   1543 				statusText: res.statusMessage,
   1544 				headers: headers,
   1545 				size: request.size,
   1546 				timeout: request.timeout,
   1547 				counter: request.counter
   1548 			};
   1549 
   1550 			// HTTP-network fetch step 12.1.1.3
   1551 			const codings = headers.get('Content-Encoding');
   1552 
   1553 			// HTTP-network fetch step 12.1.1.4: handle content codings
   1554 
   1555 			// in following scenarios we ignore compression support
   1556 			// 1. compression support is disabled
   1557 			// 2. HEAD request
   1558 			// 3. no Content-Encoding header
   1559 			// 4. no content response (204)
   1560 			// 5. content not modified response (304)
   1561 			if (!request.compress || request.method === 'HEAD' || codings === null || res.statusCode === 204 || res.statusCode === 304) {
   1562 				response = new Response(body, response_options);
   1563 				resolve(response);
   1564 				return;
   1565 			}
   1566 
   1567 			// For Node v6+
   1568 			// Be less strict when decoding compressed responses, since sometimes
   1569 			// servers send slightly invalid responses that are still accepted
   1570 			// by common browsers.
   1571 			// Always using Z_SYNC_FLUSH is what cURL does.
   1572 			const zlibOptions = {
   1573 				flush: zlib.Z_SYNC_FLUSH,
   1574 				finishFlush: zlib.Z_SYNC_FLUSH
   1575 			};
   1576 
   1577 			// for gzip
   1578 			if (codings == 'gzip' || codings == 'x-gzip') {
   1579 				body = body.pipe(zlib.createGunzip(zlibOptions));
   1580 				response = new Response(body, response_options);
   1581 				resolve(response);
   1582 				return;
   1583 			}
   1584 
   1585 			// for deflate
   1586 			if (codings == 'deflate' || codings == 'x-deflate') {
   1587 				// handle the infamous raw deflate response from old servers
   1588 				// a hack for old IIS and Apache servers
   1589 				const raw = res.pipe(new PassThrough$1());
   1590 				raw.once('data', function (chunk) {
   1591 					// see http://stackoverflow.com/questions/37519828
   1592 					if ((chunk[0] & 0x0F) === 0x08) {
   1593 						body = body.pipe(zlib.createInflate());
   1594 					} else {
   1595 						body = body.pipe(zlib.createInflateRaw());
   1596 					}
   1597 					response = new Response(body, response_options);
   1598 					resolve(response);
   1599 				});
   1600 				return;
   1601 			}
   1602 
   1603 			// for br
   1604 			if (codings == 'br' && typeof zlib.createBrotliDecompress === 'function') {
   1605 				body = body.pipe(zlib.createBrotliDecompress());
   1606 				response = new Response(body, response_options);
   1607 				resolve(response);
   1608 				return;
   1609 			}
   1610 
   1611 			// otherwise, use response as-is
   1612 			response = new Response(body, response_options);
   1613 			resolve(response);
   1614 		});
   1615 
   1616 		writeToStream(req, request);
   1617 	});
   1618 }
   1619 /**
   1620  * Redirect code matching
   1621  *
   1622  * @param   Number   code  Status code
   1623  * @return  Boolean
   1624  */
   1625 fetch.isRedirect = function (code) {
   1626 	return code === 301 || code === 302 || code === 303 || code === 307 || code === 308;
   1627 };
   1628 
   1629 // expose Promise
   1630 fetch.Promise = global.Promise;
   1631 
   1632 export default fetch;
   1633 export { Headers, Request, Response, FetchError };