text: 
  // test tools
  import chai from 'chai';
  import chaiPromised from 'chai-as-promised';
  import chaiIterator from 'chai-iterator';
  import chaiString from 'chai-string';
  import then from 'promise';
  import resumer from 'resumer';
  import FormData from 'form-data';
  import stringToArrayBuffer from 'string-to-arraybuffer';
  import URLSearchParams_Polyfill from 'url-search-params';
  import { URL } from 'whatwg-url';
  import { AbortController } from 'abortcontroller-polyfill/dist/abortcontroller';
  import AbortController2 from 'abort-controller';
  
  const { spawn } = require('child_process');
  const http = require('http');
  const fs = require('fs');
  const path = require('path');
  const stream = require('stream');
  const { parse: parseURL, URLSearchParams } = require('url');
  const { lookup } = require('dns');
  const vm = require('vm');
  
  const {
  	ArrayBuffer: VMArrayBuffer,
  	Uint8Array: VMUint8Array
  } = vm.runInNewContext('this');
  
  let convert;
  try { convert = require('encoding').convert; } catch(e) { }
  
  chai.use(chaiPromised);
  chai.use(chaiIterator);
  chai.use(chaiString);
  const expect = chai.expect;
  
  import TestServer from './server';
  
  // test subjects
  import fetch, {
  	FetchError,
  	Headers,
  	Request,
  	Response
  } from '../src/';
  import FetchErrorOrig from '../src/fetch-error.js';
  import HeadersOrig from '../src/headers.js';
  import RequestOrig from '../src/request.js';
  import ResponseOrig from '../src/response.js';
  import Body from '../src/body.js';
  import Blob from '../src/blob.js';
  import zlib from "zlib";
  
  const supportToString = ({
  	[Symbol.toStringTag]: 'z'
  }).toString() === '[object z]';
  
  const supportStreamDestroy = 'destroy' in stream.Readable.prototype;
  
  const local = new TestServer();
  const base = `http://${local.hostname}:${local.port}/`;
  
  before(done => {
  	local.start(done);
  });
  
  after(done => {
  	local.stop(done);
  });
  
  describe('node-fetch', () => {
  	it('should return a promise', function() {
  		const url = `${base}hello`;
  		const p = fetch(url);
  		expect(p).to.be.an.instanceof(fetch.Promise);
  		expect(p).to.have.property('then');
  	});
  
  	it('should allow custom promise', function() {
  		const url = `${base}hello`;
  		const old = fetch.Promise;
  		fetch.Promise = then;
  		expect(fetch(url)).to.be.an.instanceof(then);
  		expect(fetch(url)).to.not.be.an.instanceof(old);
  		fetch.Promise = old;
  	});
  
  	it('should throw error when no promise implementation are found', function() {
  		const url = `${base}hello`;
  		const old = fetch.Promise;
  		fetch.Promise = undefined;
  		expect(() => {
  			fetch(url)
  		}).to.throw(Error);
  		fetch.Promise = old;
  	});
  
  	it('should expose Headers, Response and Request constructors', function() {
  		expect(FetchError).to.equal(FetchErrorOrig);
  		expect(Headers).to.equal(HeadersOrig);
  		expect(Response).to.equal(ResponseOrig);
  		expect(Request).to.equal(RequestOrig);
  	});
  
  	(supportToString ? it : it.skip)('should support proper toString output for Headers, Response and Request objects', function() {
  		expect(new Headers().toString()).to.equal('[object Headers]');
  		expect(new Response().toString()).to.equal('[object Response]');
  		expect(new Request(base).toString()).to.equal('[object Request]');
  	});
  
  	it('should reject with error if url is protocol relative', function() {
  		const url = '//example.com/';
  		return expect(fetch(url)).to.eventually.be.rejectedWith(TypeError, 'Only absolute URLs are supported');
  	});
  
  	it('should reject with error if url is relative path', function() {
  		const url = '/some/path';
  		return expect(fetch(url)).to.eventually.be.rejectedWith(TypeError, 'Only absolute URLs are supported');
  	});
  
  	it('should reject with error if protocol is unsupported', function() {
  		const url = 'ftp://example.com/';
  		return expect(fetch(url)).to.eventually.be.rejectedWith(TypeError, 'Only HTTP(S) protocols are supported');
  	});
  
  	it('should reject with error on network failure', function() {
  		const url = 'http://localhost:50000/';
  		return expect(fetch(url)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.include({ type: 'system', code: 'ECONNREFUSED', errno: 'ECONNREFUSED' });
  	});
  
  	it('should resolve into response', function() {
  		const url = `${base}hello`;
  		return fetch(url).then(res => {
  			expect(res).to.be.an.instanceof(Response);
  			expect(res.headers).to.be.an.instanceof(Headers);
  			expect(res.body).to.be.an.instanceof(stream.Transform);
  			expect(res.bodyUsed).to.be.false;
  
  			expect(res.url).to.equal(url);
  			expect(res.ok).to.be.true;
  			expect(res.status).to.equal(200);
  			expect(res.statusText).to.equal('OK');
  		});
  	});
  
  	it('should accept plain text response', function() {
  		const url = `${base}plain`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				expect(result).to.be.a('string');
  				expect(result).to.equal('text');
  			});
  		});
  	});
  
  	it('should accept html response (like plain text)', function() {
  		const url = `${base}html`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/html');
  			return res.text().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				expect(result).to.be.a('string');
  				expect(result).to.equal('<html></html>');
  			});
  		});
  	});
  
  	it('should accept json response', function() {
  		const url = `${base}json`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('application/json');
  			return res.json().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				expect(result).to.be.an('object');
  				expect(result).to.deep.equal({ name: 'value' });
  			});
  		});
  	});
  
  	it('should send request with custom headers', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: { 'x-custom-header': 'abc' }
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.headers['x-custom-header']).to.equal('abc');
  		});
  	});
  
  	it('should accept headers instance', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: new Headers({ 'x-custom-header': 'abc' })
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.headers['x-custom-header']).to.equal('abc');
  		});
  	});
  
  	it('should accept custom host header', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: {
  				host: 'example.com'
  			}
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.headers['host']).to.equal('example.com');
  		});
  	});
  
  	it('should accept custom HoSt header', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: {
  				HoSt: 'example.com'
  			}
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.headers['host']).to.equal('example.com');
  		});
  	});
  
  	it('should follow redirect code 301', function() {
  		const url = `${base}redirect/301`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			expect(res.ok).to.be.true;
  		});
  	});
  
  	it('should follow redirect code 302', function() {
  		const url = `${base}redirect/302`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should follow redirect code 303', function() {
  		const url = `${base}redirect/303`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should follow redirect code 307', function() {
  		const url = `${base}redirect/307`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should follow redirect code 308', function() {
  		const url = `${base}redirect/308`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should follow redirect chain', function() {
  		const url = `${base}redirect/chain`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should follow POST request redirect code 301 with GET', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			method: 'POST',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(result => {
  				expect(result.method).to.equal('GET');
  				expect(result.body).to.equal('');
  			});
  		});
  	});
  
  	it('should follow PATCH request redirect code 301 with PATCH', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			method: 'PATCH',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(res => {
  				expect(res.method).to.equal('PATCH');
  				expect(res.body).to.equal('a=1');
  			});
  		});
  	});
  
  	it('should follow POST request redirect code 302 with GET', function() {
  		const url = `${base}redirect/302`;
  		const opts = {
  			method: 'POST',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(result => {
  				expect(result.method).to.equal('GET');
  				expect(result.body).to.equal('');
  			});
  		});
  	});
  
  	it('should follow PATCH request redirect code 302 with PATCH', function() {
  		const url = `${base}redirect/302`;
  		const opts = {
  			method: 'PATCH',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(res => {
  				expect(res.method).to.equal('PATCH');
  				expect(res.body).to.equal('a=1');
  			});
  		});
  	});
  
  	it('should follow redirect code 303 with GET', function() {
  		const url = `${base}redirect/303`;
  		const opts = {
  			method: 'PUT',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(result => {
  				expect(result.method).to.equal('GET');
  				expect(result.body).to.equal('');
  			});
  		});
  	});
  
  	it('should follow PATCH request redirect code 307 with PATCH', function() {
  		const url = `${base}redirect/307`;
  		const opts = {
  			method: 'PATCH',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  			return res.json().then(result => {
  				expect(result.method).to.equal('PATCH');
  				expect(result.body).to.equal('a=1');
  			});
  		});
  	});
  
  	it('should not follow non-GET redirect if body is a readable stream', function() {
  		const url = `${base}redirect/307`;
  		const opts = {
  			method: 'PATCH',
  			body: resumer().queue('a=1').end()
  		};
  		return expect(fetch(url, opts)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('type', 'unsupported-redirect');
  	});
  
  	it('should obey maximum redirect, reject case', function() {
  		const url = `${base}redirect/chain`;
  		const opts = {
  			follow: 1
  		}
  		return expect(fetch(url, opts)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('type', 'max-redirect');
  	});
  
  	it('should obey redirect chain, resolve case', function() {
  		const url = `${base}redirect/chain`;
  		const opts = {
  			follow: 2
  		}
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should allow not following redirect', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			follow: 0
  		}
  		return expect(fetch(url, opts)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('type', 'max-redirect');
  	});
  
  	it('should support redirect mode, manual flag', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			redirect: 'manual'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.status).to.equal(301);
  			expect(res.headers.get('location')).to.equal(`${base}inspect`);
  		});
  	});
  
  	it('should support redirect mode, error flag', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			redirect: 'error'
  		};
  		return expect(fetch(url, opts)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('type', 'no-redirect');
  	});
  
  	it('should support redirect mode, manual flag when there is no redirect', function() {
  		const url = `${base}hello`;
  		const opts = {
  			redirect: 'manual'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.status).to.equal(200);
  			expect(res.headers.get('location')).to.be.null;
  		});
  	});
  
  	it('should follow redirect code 301 and keep existing headers', function() {
  		const url = `${base}redirect/301`;
  		const opts = {
  			headers: new Headers({ 'x-custom-header': 'abc' })
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(`${base}inspect`);
  			return res.json();
  		}).then(res => {
  			expect(res.headers['x-custom-header']).to.equal('abc');
  		});
  	});
  
  	it('should treat broken redirect as ordinary response (follow)', function() {
  		const url = `${base}redirect/no-location`;
  		return fetch(url).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.status).to.equal(301);
  			expect(res.headers.get('location')).to.be.null;
  		});
  	});
  
  	it('should treat broken redirect as ordinary response (manual)', function() {
  		const url = `${base}redirect/no-location`;
  		const opts = {
  			redirect: 'manual'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.status).to.equal(301);
  			expect(res.headers.get('location')).to.be.null;
  		});
  	});
  
  	it('should ignore invalid headers', function() {
  		const url = `${base}invalid-header`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('Invalid-Header')).to.be.null;
  			expect(res.headers.get('Invalid-Header-Value')).to.be.null;
  			expect(res.headers.get('Set-Cookie')).to.be.null;
  			expect(Array.from(res.headers.keys()).length).to.equal(4);
  			expect(res.headers.has('Connection')).to.be.true;
  			expect(res.headers.has('Content-Type')).to.be.true;
  			expect(res.headers.has('Date')).to.be.true;
  			expect(res.headers.has('Transfer-Encoding')).to.be.true;
  		});
  	});
  
  	it('should handle client-error response', function() {
  		const url = `${base}error/400`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			expect(res.status).to.equal(400);
  			expect(res.statusText).to.equal('Bad Request');
  			expect(res.ok).to.be.false;
  			return res.text().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				expect(result).to.be.a('string');
  				expect(result).to.equal('client error');
  			});
  		});
  	});
  
  	it('should handle server-error response', function() {
  		const url = `${base}error/500`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			expect(res.status).to.equal(500);
  			expect(res.statusText).to.equal('Internal Server Error');
  			expect(res.ok).to.be.false;
  			return res.text().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				expect(result).to.be.a('string');
  				expect(result).to.equal('server error');
  			});
  		});
  	});
  
  	it('should handle network-error response', function() {
  		const url = `${base}error/reset`;
  		return expect(fetch(url)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('code', 'ECONNRESET');
  	});
  
  	it('should handle DNS-error response', function() {
  		const url = 'http://domain.invalid';
  		return expect(fetch(url)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('code', 'ENOTFOUND');
  	});
  
  	it('should reject invalid json response', function() {
  		const url = `${base}error/json`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('application/json');
  			return expect(res.json()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.include({ type: 'invalid-json' });
  		});
  	});
  
  	it('should handle no content response', function() {
  		const url = `${base}no-content`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(204);
  			expect(res.statusText).to.equal('No Content');
  			expect(res.ok).to.be.true;
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.be.empty;
  			});
  		});
  	});
  
  	it('should reject when trying to parse no content response as json', function() {
  		const url = `${base}no-content`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(204);
  			expect(res.statusText).to.equal('No Content');
  			expect(res.ok).to.be.true;
  			return expect(res.json()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.include({ type: 'invalid-json' });
  		});
  	});
  
  	it('should handle no content response with gzip encoding', function() {
  		const url = `${base}no-content/gzip`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(204);
  			expect(res.statusText).to.equal('No Content');
  			expect(res.headers.get('content-encoding')).to.equal('gzip');
  			expect(res.ok).to.be.true;
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.be.empty;
  			});
  		});
  	});
  
  	it('should handle not modified response', function() {
  		const url = `${base}not-modified`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(304);
  			expect(res.statusText).to.equal('Not Modified');
  			expect(res.ok).to.be.false;
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.be.empty;
  			});
  		});
  	});
  
  	it('should handle not modified response with gzip encoding', function() {
  		const url = `${base}not-modified/gzip`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(304);
  			expect(res.statusText).to.equal('Not Modified');
  			expect(res.headers.get('content-encoding')).to.equal('gzip');
  			expect(res.ok).to.be.false;
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.be.empty;
  			});
  		});
  	});
  
  	it('should decompress gzip response', function() {
  		const url = `${base}gzip`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('hello world');
  			});
  		});
  	});
  
  	it('should decompress slightly invalid gzip response', function() {
  		const url = `${base}gzip-truncated`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('hello world');
  			});
  		});
  	});
  
  	it('should decompress deflate response', function() {
  		const url = `${base}deflate`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('hello world');
  			});
  		});
  	});
  
  	it('should decompress deflate raw response from old apache server', function() {
  		const url = `${base}deflate-raw`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('hello world');
  			});
  		});
  	});
  
  	it('should decompress brotli response', function() {
  		if(typeof zlib.createBrotliDecompress !== 'function') this.skip();
  		const url = `${base}brotli`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('hello world');
  			});
  		});
  	});
  
  	it('should handle no content response with brotli encoding', function() {
  		if(typeof zlib.createBrotliDecompress !== 'function') this.skip();
  		const url = `${base}no-content/brotli`;
  		return fetch(url).then(res => {
  			expect(res.status).to.equal(204);
  			expect(res.statusText).to.equal('No Content');
  			expect(res.headers.get('content-encoding')).to.equal('br');
  			expect(res.ok).to.be.true;
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.be.empty;
  			});
  		});
  	});
  
  	it('should skip decompression if unsupported', function() {
  		const url = `${base}sdch`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.equal('fake sdch string');
  			});
  		});
  	});
  
  	it('should reject if response compression is invalid', function() {
  		const url = `${base}invalid-content-encoding`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return expect(res.text()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.have.property('code', 'Z_DATA_ERROR');
  		});
  	});
  
  	it('should handle errors on the body stream even if it is not used', function(done) {
  		const url = `${base}invalid-content-encoding`;
  		fetch(url)
  			.then(res => {
  				expect(res.status).to.equal(200);
  			})
  			.catch(() => {})
  			.then(() => {
  				// Wait a few ms to see if a uncaught error occurs
  				setTimeout(() => {
  					done();
  				}, 50);
  			});
  	});
  
  	it('should collect handled errors on the body stream to reject if the body is used later', function() {
  
  		function delay(value) {
  			return new Promise((resolve) => {
  				setTimeout(() => {
  					resolve(value)
  				}, 100);
  			});
  		}
  
  		const url = `${base}invalid-content-encoding`;
  		return fetch(url).then(delay).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return expect(res.text()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.have.property('code', 'Z_DATA_ERROR');
  		});
  	});
  
  	it('should allow disabling auto decompression', function() {
  		const url = `${base}gzip`;
  		const opts = {
  			compress: false
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(result).to.be.a('string');
  				expect(result).to.not.equal('hello world');
  			});
  		});
  	});
  
  	it('should not overwrite existing accept-encoding header when auto decompression is true', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			compress: true,
  			headers: {
  				'Accept-Encoding': 'gzip'
  			}
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.headers['accept-encoding']).to.equal('gzip');
  		});
  	});
  
  	it('should allow custom timeout', function() {
  		this.timeout(500);
  		const url = `${base}timeout`;
  		const opts = {
  			timeout: 100
  		};
  		return expect(fetch(url, opts)).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.have.property('type', 'request-timeout');
  	});
  
  	it('should allow custom timeout on response body', function() {
  		this.timeout(500);
  		const url = `${base}slow`;
  		const opts = {
  			timeout: 100
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.ok).to.be.true;
  			return expect(res.text()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.have.property('type', 'body-timeout');
  		});
  	});
  
  	it('should clear internal timeout on fetch response', function (done) {
  		this.timeout(2000);
  		spawn('node', ['-e', `require('./')('${base}hello', { timeout: 10000 })`])
  			.on('exit', () => {
  				done();
  			});
  	});
  
  	it('should clear internal timeout on fetch redirect', function (done) {
  		this.timeout(2000);
  		spawn('node', ['-e', `require('./')('${base}redirect/301', { timeout: 10000 })`])
  			.on('exit', () => {
  				done();
  			});
  	});
  
  	it('should clear internal timeout on fetch error', function (done) {
  		this.timeout(2000);
  		spawn('node', ['-e', `require('./')('${base}error/reset', { timeout: 10000 })`])
  			.on('exit', () => {
  				done();
  			});
  	});
  
  	it('should support request cancellation with signal', function () {
  		this.timeout(500);
  		const controller = new AbortController();
  		const controller2 = new AbortController2();
  
  		const fetches = [
  			fetch(`${base}timeout`, { signal: controller.signal }),
  			fetch(`${base}timeout`, { signal: controller2.signal }),
  			fetch(
  				`${base}timeout`,
  				{
  					method: 'POST',
  					signal: controller.signal,
  					headers: {
  						'Content-Type': 'application/json',
  						body: JSON.stringify({ hello: 'world' })
  					}
  				}
  			)
  		];
  		setTimeout(() => {
  			controller.abort();
  			controller2.abort();
  		}, 100);
  
  		return Promise.all(fetches.map(fetched => expect(fetched)
  			.to.eventually.be.rejected
  			.and.be.an.instanceOf(Error)
  			.and.include({
  				type: 'aborted',
  				name: 'AbortError',
  			})
  		));
  	});
  
  	it('should reject immediately if signal has already been aborted', function () {
  		const url = `${base}timeout`;
  		const controller = new AbortController();
  		const opts = {
  			signal: controller.signal
  		};
  		controller.abort();
  		const fetched = fetch(url, opts);
  		return expect(fetched).to.eventually.be.rejected
  			.and.be.an.instanceOf(Error)
  			.and.include({
  				type: 'aborted',
  				name: 'AbortError',
  			});
  	});
  
  	it('should clear internal timeout when request is cancelled with an AbortSignal', function(done) {
  		this.timeout(2000);
  		const script = `
  			var AbortController = require('abortcontroller-polyfill/dist/cjs-ponyfill').AbortController;
  			var controller = new AbortController();
  			require('./')(
  				'${base}timeout',
  				{ signal: controller.signal, timeout: 10000 }
  			);
  			setTimeout(function () { controller.abort(); }, 100);
  		`
  		spawn('node', ['-e', script])
  			.on('exit', () => {
  				done();
  			});
  	});
  
  	it('should remove internal AbortSignal event listener after request is aborted', function () {
  		const controller = new AbortController();
  		const { signal } = controller;
  		const promise = fetch(
  			`${base}timeout`,
  			{ signal }
  		);
  		const result = expect(promise).to.eventually.be.rejected
  			.and.be.an.instanceof(Error)
  			.and.have.property('name', 'AbortError')
  			.then(() => {
  				expect(signal.listeners.abort.length).to.equal(0);
  			});
  		controller.abort();
  		return result;
  	});
  
  	it('should allow redirects to be aborted', function() {
  		const abortController = new AbortController();
  		const request = new Request(`${base}redirect/slow`, {
  			signal: abortController.signal
  		});
  		setTimeout(() => {
  			abortController.abort();
  		}, 50);
  		return expect(fetch(request)).to.be.eventually.rejected
  			.and.be.an.instanceOf(Error)
  			.and.have.property('name', 'AbortError');
  	});
  
  	it('should allow redirected response body to be aborted', function() {
  		const abortController = new AbortController();
  		const request = new Request(`${base}redirect/slow-stream`, {
  			signal: abortController.signal
  		});
  		return expect(fetch(request).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			const result = res.text();
  			abortController.abort();
  			return result;
  		})).to.be.eventually.rejected
  			.and.be.an.instanceOf(Error)
  			.and.have.property('name', 'AbortError');
  	});
  
  	it('should remove internal AbortSignal event listener after request and response complete without aborting', () => {
  		const controller = new AbortController();
  		const { signal } = controller;
  		const fetchHtml = fetch(`${base}html`, { signal })
  			.then(res => res.text());
  		const fetchResponseError = fetch(`${base}error/reset`, { signal });
  		const fetchRedirect = fetch(`${base}redirect/301`, { signal }).then(res => res.json());
  		return Promise.all([
  			expect(fetchHtml).to.eventually.be.fulfilled.and.equal('<html></html>'),
  			expect(fetchResponseError).to.be.eventually.rejected,
  			expect(fetchRedirect).to.eventually.be.fulfilled,
  		]).then(() => {
  			expect(signal.listeners.abort.length).to.equal(0)
  		});
  	});
  
  	it('should reject response body with AbortError when aborted before stream has been read completely', () => {
  		const controller = new AbortController();
  		return expect(fetch(
  			`${base}slow`,
  			{ signal: controller.signal }
  		))
  			.to.eventually.be.fulfilled
  			.then((res) => {
  				const promise = res.text();
  				controller.abort();
  				return expect(promise)
  					.to.eventually.be.rejected
  					.and.be.an.instanceof(Error)
  					.and.have.property('name', 'AbortError');
  			});
  	});
  
  	it('should reject response body methods immediately with AbortError when aborted before stream is disturbed', () => {
  		const controller = new AbortController();
  		return expect(fetch(
  			`${base}slow`,
  			{ signal: controller.signal }
  		))
  			.to.eventually.be.fulfilled
  			.then((res) => {
  				controller.abort();
  				return expect(res.text())
  					.to.eventually.be.rejected
  					.and.be.an.instanceof(Error)
  					.and.have.property('name', 'AbortError');
  			});
  	});
  
  	it('should emit error event to response body with an AbortError when aborted before underlying stream is closed', (done) => {
  		const controller = new AbortController();
  		expect(fetch(
  			`${base}slow`,
  			{ signal: controller.signal }
  		))
  			.to.eventually.be.fulfilled
  			.then((res) => {
  				res.body.on('error', (err) => {
  					expect(err)
  						.to.be.an.instanceof(Error)
  						.and.have.property('name', 'AbortError');
  					done();
  				});
  				controller.abort();
  			});
  	});
  
  	(supportStreamDestroy ? it : it.skip)('should cancel request body of type Stream with AbortError when aborted', () => {
  		const controller = new AbortController();
  		const body = new stream.Readable({ objectMode: true });
  		body._read = () => {};
  		const promise = fetch(
  			`${base}slow`,
  			{ signal: controller.signal, body, method: 'POST' }
  		);
  
  		const result = Promise.all([
  			new Promise((resolve, reject) => {
  				body.on('error', (error) => {
  					try {
  						expect(error).to.be.an.instanceof(Error).and.have.property('name', 'AbortError')
  						resolve();
  					} catch (err) {
  						reject(err);
  					}
  				});
  			}),
  			expect(promise).to.eventually.be.rejected
  				.and.be.an.instanceof(Error)
  				.and.have.property('name', 'AbortError')
  		]);
  
  		controller.abort();
  
  		return result;
  	});
  
  	(supportStreamDestroy ? it.skip : it)('should immediately reject when attempting to cancel streamed Requests in node < 8', () => {
  		const controller = new AbortController();
  		const body = new stream.Readable({ objectMode: true });
  		body._read = () => {};
  		const promise = fetch(
  			`${base}slow`,
  			{ signal: controller.signal, body, method: 'POST' }
  		);
  
  		return expect(promise).to.eventually.be.rejected
  			.and.be.an.instanceof(Error)
  			.and.have.property('message').includes('not supported');
  	});
  
  	it('should throw a TypeError if a signal is not of type AbortSignal', () => {
  		return Promise.all([
  			expect(fetch(`${base}inspect`, { signal: {} }))
  				.to.be.eventually.rejected
  				.and.be.an.instanceof(TypeError)
  				.and.have.property('message').includes('AbortSignal'),
  			expect(fetch(`${base}inspect`, { signal: '' }))
  				.to.be.eventually.rejected
  				.and.be.an.instanceof(TypeError)
  				.and.have.property('message').includes('AbortSignal'),
  			expect(fetch(`${base}inspect`, { signal: Object.create(null) }))
  				.to.be.eventually.rejected
  				.and.be.an.instanceof(TypeError)
  				.and.have.property('message').includes('AbortSignal'),
  		]);
  	});
  
  	it('should set default User-Agent', function () {
  		const url = `${base}inspect`;
  		return fetch(url).then(res => res.json()).then(res => {
  			expect(res.headers['user-agent']).to.startWith('node-fetch/');
  		});
  	});
  
  	it('should allow setting User-Agent', function () {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: {
  				'user-agent': 'faked'
  			}
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.headers['user-agent']).to.equal('faked');
  		});
  	});
  
  	it('should set default Accept header', function () {
  		const url = `${base}inspect`;
  		fetch(url).then(res => res.json()).then(res => {
  			expect(res.headers.accept).to.equal('*/*');
  		});
  	});
  
  	it('should allow setting Accept header', function () {
  		const url = `${base}inspect`;
  		const opts = {
  			headers: {
  				'accept': 'application/json'
  			}
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.headers.accept).to.equal('application/json');
  		});
  	});
  
  	it('should allow POST request', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('0');
  		});
  	});
  
  	it('should allow POST request with string body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.equal('text/plain;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow POST request with buffer body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: Buffer.from('a=1', 'utf-8')
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow POST request with ArrayBuffer body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: stringToArrayBuffer('Hello, world!\n')
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('Hello, world!\n');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('14');
  		});
  	});
  
  	it('should allow POST request with ArrayBuffer body from a VM context', function() {
  		// TODO: Node.js v4 doesn't support ArrayBuffer from other contexts, so we skip this test, drop this check once Node.js v4 support is not needed
  		try {
  			Buffer.from(new VMArrayBuffer());
  		} catch (err) {
  			this.skip();
  		}
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new VMUint8Array(Buffer.from('Hello, world!\n')).buffer
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('Hello, world!\n');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('14');
  		});
  	});
  
  	it('should allow POST request with ArrayBufferView (Uint8Array) body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new Uint8Array(stringToArrayBuffer('Hello, world!\n'))
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('Hello, world!\n');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('14');
  		});
  	});
  
  	it('should allow POST request with ArrayBufferView (DataView) body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new DataView(stringToArrayBuffer('Hello, world!\n'))
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('Hello, world!\n');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('14');
  		});
  	});
  
  	it('should allow POST request with ArrayBufferView (Uint8Array) body from a VM context', function() {
  		// TODO: Node.js v4 doesn't support ArrayBufferView from other contexts, so we skip this test, drop this check once Node.js v4 support is not needed
  		try {
  			Buffer.from(new VMArrayBuffer());
  		} catch (err) {
  			this.skip();
  		}
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new VMUint8Array(Buffer.from('Hello, world!\n'))
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('Hello, world!\n');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('14');
  		});
  	});
  
  	// TODO: Node.js v4 doesn't support necessary Buffer API, so we skip this test, drop this check once Node.js v4 support is not needed
  	(Buffer.from.length === 3 ? it : it.skip)('should allow POST request with ArrayBufferView (Uint8Array, offset, length) body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new Uint8Array(stringToArrayBuffer('Hello, world!\n'), 7, 6)
  		};
  		return fetch(url, opts).then(res => res.json()).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('world!');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('6');
  		});
  	});
  
  	it('should allow POST request with blob body without type', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new Blob(['a=1'])
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow POST request with blob body with type', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: new Blob(['a=1'], {
  				type: 'text/plain;charset=UTF-8'
  			})
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.equal('text/plain;charset=utf-8');
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow POST request with readable stream as body', function() {
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.equal('chunked');
  			expect(res.headers['content-type']).to.be.undefined;
  			expect(res.headers['content-length']).to.be.undefined;
  		});
  	});
  
  	it('should allow POST request with form-data as body', function() {
  		const form = new FormData();
  		form.append('a','1');
  
  		const url = `${base}multipart`;
  		const opts = {
  			method: 'POST',
  			body: form
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.startWith('multipart/form-data;boundary=');
  			expect(res.headers['content-length']).to.be.a('string');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	it('should allow POST request with form-data using stream as body', function() {
  		const form = new FormData();
  		form.append('my_field', fs.createReadStream(path.join(__dirname, 'dummy.txt')));
  
  		const url = `${base}multipart`;
  		const opts = {
  			method: 'POST',
  			body: form
  		};
  
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.startWith('multipart/form-data;boundary=');
  			expect(res.headers['content-length']).to.be.undefined;
  			expect(res.body).to.contain('my_field=');
  		});
  	});
  
  	it('should allow POST request with form-data as body and custom headers', function() {
  		const form = new FormData();
  		form.append('a','1');
  
  		const headers = form.getHeaders();
  		headers['b'] = '2';
  
  		const url = `${base}multipart`;
  		const opts = {
  			method: 'POST',
  			body: form,
  			headers
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.startWith('multipart/form-data; boundary=');
  			expect(res.headers['content-length']).to.be.a('string');
  			expect(res.headers.b).to.equal('2');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	it('should allow POST request with object body', function() {
  		const url = `${base}inspect`;
  		// note that fetch simply calls tostring on an object
  		const opts = {
  			method: 'POST',
  			body: { a: 1 }
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('[object Object]');
  			expect(res.headers['content-type']).to.equal('text/plain;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('15');
  		});
  	});
  
  	const itUSP = typeof URLSearchParams === 'function' ? it : it.skip;
  
  	itUSP('constructing a Response with URLSearchParams as body should have a Content-Type', function() {
  		const params = new URLSearchParams();
  		const res = new Response(params);
  		res.headers.get('Content-Type');
  		expect(res.headers.get('Content-Type')).to.equal('application/x-www-form-urlencoded;charset=UTF-8');
  	});
  
  	itUSP('constructing a Request with URLSearchParams as body should have a Content-Type', function() {
  		const params = new URLSearchParams();
  		const req = new Request(base, { method: 'POST', body: params });
  		expect(req.headers.get('Content-Type')).to.equal('application/x-www-form-urlencoded;charset=UTF-8');
  	});
  
  	itUSP('Reading a body with URLSearchParams should echo back the result', function() {
  		const params = new URLSearchParams();
  		params.append('a','1');
  		return new Response(params).text().then(text => {
  			expect(text).to.equal('a=1');
  		});
  	});
  
  	// Body should been cloned...
  	itUSP('constructing a Request/Response with URLSearchParams and mutating it should not affected body', function() {
  		const params = new URLSearchParams();
  		const req = new Request(`${base}inspect`, { method: 'POST', body: params })
  		params.append('a','1')
  		return req.text().then(text => {
  			expect(text).to.equal('');
  		});
  	});
  
  	itUSP('should allow POST request with URLSearchParams as body', function() {
  		const params = new URLSearchParams();
  		params.append('a','1');
  
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: params,
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.equal('application/x-www-form-urlencoded;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('3');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	itUSP('should still recognize URLSearchParams when extended', function() {
  		class CustomSearchParams extends URLSearchParams {}
  		const params = new CustomSearchParams();
  		params.append('a','1');
  
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: params,
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.equal('application/x-www-form-urlencoded;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('3');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	/* for 100% code coverage, checks for duck-typing-only detection
  	 * where both constructor.name and brand tests fail */
  	it('should still recognize URLSearchParams when extended from polyfill', function() {
  		class CustomPolyfilledSearchParams extends URLSearchParams_Polyfill {}
  		const params = new CustomPolyfilledSearchParams();
  		params.append('a','1');
  
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'POST',
  			body: params,
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.headers['content-type']).to.equal('application/x-www-form-urlencoded;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('3');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	it('should overwrite Content-Length if possible', function() {
  		const url = `${base}inspect`;
  		// note that fetch simply calls tostring on an object
  		const opts = {
  			method: 'POST',
  			headers: {
  				'Content-Length': '1000'
  			},
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('POST');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-type']).to.equal('text/plain;charset=UTF-8');
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow PUT request', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'PUT',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('PUT');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	it('should allow DELETE request', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'DELETE'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('DELETE');
  		});
  	});
  
  	it('should allow DELETE request with string body', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'DELETE',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('DELETE');
  			expect(res.body).to.equal('a=1');
  			expect(res.headers['transfer-encoding']).to.be.undefined;
  			expect(res.headers['content-length']).to.equal('3');
  		});
  	});
  
  	it('should allow PATCH request', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			method: 'PATCH',
  			body: 'a=1'
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.method).to.equal('PATCH');
  			expect(res.body).to.equal('a=1');
  		});
  	});
  
  	it('should allow HEAD request', function() {
  		const url = `${base}hello`;
  		const opts = {
  			method: 'HEAD'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(200);
  			expect(res.statusText).to.equal('OK');
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			expect(res.body).to.be.an.instanceof(stream.Transform);
  			return res.text();
  		}).then(text => {
  			expect(text).to.equal('');
  		});
  	});
  
  	it('should allow HEAD request with content-encoding header', function() {
  		const url = `${base}error/404`;
  		const opts = {
  			method: 'HEAD'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(404);
  			expect(res.headers.get('content-encoding')).to.equal('gzip');
  			return res.text();
  		}).then(text => {
  			expect(text).to.equal('');
  		});
  	});
  
  	it('should allow OPTIONS request', function() {
  		const url = `${base}options`;
  		const opts = {
  			method: 'OPTIONS'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(200);
  			expect(res.statusText).to.equal('OK');
  			expect(res.headers.get('allow')).to.equal('GET, HEAD, OPTIONS');
  			expect(res.body).to.be.an.instanceof(stream.Transform);
  		});
  	});
  
  	it('should reject decoding body twice', function() {
  		const url = `${base}plain`;
  		return fetch(url).then(res => {
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return res.text().then(result => {
  				expect(res.bodyUsed).to.be.true;
  				return expect(res.text()).to.eventually.be.rejectedWith(Error);
  			});
  		});
  	});
  
  	it('should support maximum response size, multiple chunk', function() {
  		const url = `${base}size/chunk`;
  		const opts = {
  			size: 5
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(200);
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return expect(res.text()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.have.property('type', 'max-size');
  		});
  	});
  
  	it('should support maximum response size, single chunk', function() {
  		const url = `${base}size/long`;
  		const opts = {
  			size: 5
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(200);
  			expect(res.headers.get('content-type')).to.equal('text/plain');
  			return expect(res.text()).to.eventually.be.rejected
  				.and.be.an.instanceOf(FetchError)
  				.and.have.property('type', 'max-size');
  		});
  	});
  
  	it('should allow piping response body as stream', function() {
  		const url = `${base}hello`;
  		return fetch(url).then(res => {
  			expect(res.body).to.be.an.instanceof(stream.Transform);
  			return streamToPromise(res.body, chunk => {
  				if (chunk === null) {
  					return;
  				}
  				expect(chunk.toString()).to.equal('world');
  			});
  		});
  	});
  
  	it('should allow cloning a response, and use both as stream', function() {
  		const url = `${base}hello`;
  		return fetch(url).then(res => {
  			const r1 = res.clone();
  			expect(res.body).to.be.an.instanceof(stream.Transform);
  			expect(r1.body).to.be.an.instanceof(stream.Transform);
  			const dataHandler = chunk => {
  				if (chunk === null) {
  					return;
  				}
  				expect(chunk.toString()).to.equal('world');
  			};
  
  			return Promise.all([
  				streamToPromise(res.body, dataHandler),
  				streamToPromise(r1.body, dataHandler)
  			]);
  		});
  	});
  
  	it('should allow cloning a json response and log it as text response', function() {
  		const url = `${base}json`;
  		return fetch(url).then(res => {
  			const r1 = res.clone();
  			return Promise.all([res.json(), r1.text()]).then(results => {
  				expect(results[0]).to.deep.equal({name: 'value'});
  				expect(results[1]).to.equal('{"name":"value"}');
  			});
  		});
  	});
  
  	it('should allow cloning a json response, and then log it as text response', function() {
  		const url = `${base}json`;
  		return fetch(url).then(res => {
  			const r1 = res.clone();
  			return res.json().then(result => {
  				expect(result).to.deep.equal({name: 'value'});
  				return r1.text().then(result => {
  					expect(result).to.equal('{"name":"value"}');
  				});
  			});
  		});
  	});
  
  	it('should allow cloning a json response, first log as text response, then return json object', function() {
  		const url = `${base}json`;
  		return fetch(url).then(res => {
  			const r1 = res.clone();
  			return r1.text().then(result => {
  				expect(result).to.equal('{"name":"value"}');
  				return res.json().then(result => {
  					expect(result).to.deep.equal({name: 'value'});
  				});
  			});
  		});
  	});
  
  	it('should not allow cloning a response after its been used', function() {
  		const url = `${base}hello`;
  		return fetch(url).then(res =>
  			res.text().then(result => {
  				expect(() => {
  					res.clone();
  				}).to.throw(Error);
  			})
  		);
  	});
  
  	it('should allow get all responses of a header', function() {
  		const url = `${base}cookie`;
  		return fetch(url).then(res => {
  			const expected = 'a=1, b=1';
  			expect(res.headers.get('set-cookie')).to.equal(expected);
  			expect(res.headers.get('Set-Cookie')).to.equal(expected);
  		});
  	});
  
  	it('should return all headers using raw()', function() {
  		const url = `${base}cookie`;
  		return fetch(url).then(res => {
  			const expected = [
  				'a=1',
  				'b=1'
  			];
  
  			expect(res.headers.raw()['set-cookie']).to.deep.equal(expected);
  		});
  	});
  
  	it('should allow deleting header', function() {
  		const url = `${base}cookie`;
  		return fetch(url).then(res => {
  			res.headers.delete('set-cookie');
  			expect(res.headers.get('set-cookie')).to.be.null;
  		});
  	});
  
  	it('should send request with connection keep-alive if agent is provided', function() {
  		const url = `${base}inspect`;
  		const opts = {
  			agent: new http.Agent({
  				keepAlive: true
  			})
  		};
  		return fetch(url, opts).then(res => {
  			return res.json();
  		}).then(res => {
  			expect(res.headers['connection']).to.equal('keep-alive');
  		});
  	});
  
  	it('should support fetch with Request instance', function() {
  		const url = `${base}hello`;
  		const req = new Request(url);
  		return fetch(req).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.ok).to.be.true;
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should support fetch with Node.js URL object', function() {
  		const url = `${base}hello`;
  		const urlObj = parseURL(url);
  		const req = new Request(urlObj);
  		return fetch(req).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.ok).to.be.true;
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should support fetch with WHATWG URL object', function() {
  		const url = `${base}hello`;
  		const urlObj = new URL(url);
  		const req = new Request(urlObj);
  		return fetch(req).then(res => {
  			expect(res.url).to.equal(url);
  			expect(res.ok).to.be.true;
  			expect(res.status).to.equal(200);
  		});
  	});
  
  	it('should support blob round-trip', function() {
  		const url = `${base}hello`;
  
  		let length, type;
  
  		return fetch(url).then(res => res.blob()).then(blob => {
  			const url = `${base}inspect`;
  			length = blob.size;
  			type = blob.type;
  			return fetch(url, {
  				method: 'POST',
  				body: blob
  			});
  		}).then(res => res.json()).then(({body, headers}) => {
  			expect(body).to.equal('world');
  			expect(headers['content-type']).to.equal(type);
  			expect(headers['content-length']).to.equal(String(length));
  		});
  	});
  
  	it('should support overwrite Request instance', function() {
  		const url = `${base}inspect`;
  		const req = new Request(url, {
  			method: 'POST',
  			headers: {
  				a: '1'
  			}
  		});
  		return fetch(req, {
  			method: 'GET',
  			headers: {
  				a: '2'
  			}
  		}).then(res => {
  			return res.json();
  		}).then(body => {
  			expect(body.method).to.equal('GET');
  			expect(body.headers.a).to.equal('2');
  		});
  	});
  
  	it('should support arrayBuffer(), blob(), text(), json() and buffer() method in Body constructor', function() {
  		const body = new Body('a=1');
  		expect(body).to.have.property('arrayBuffer');
  		expect(body).to.have.property('blob');
  		expect(body).to.have.property('text');
  		expect(body).to.have.property('json');
  		expect(body).to.have.property('buffer');
  	});
  
  	it('should create custom FetchError', function funcName() {
  		const systemError = new Error('system');
  		systemError.code = 'ESOMEERROR';
  
  		const err = new FetchError('test message', 'test-error', systemError);
  		expect(err).to.be.an.instanceof(Error);
  		expect(err).to.be.an.instanceof(FetchError);
  		expect(err.name).to.equal('FetchError');
  		expect(err.message).to.equal('test message');
  		expect(err.type).to.equal('test-error');
  		expect(err.code).to.equal('ESOMEERROR');
  		expect(err.errno).to.equal('ESOMEERROR');
  		expect(err.stack).to.include('funcName')
  			.and.to.startWith(`${err.name}: ${err.message}`);
  	});
  
  	it('should support https request', function() {
  		this.timeout(5000);
  		const url = 'https://github.com/';
  		const opts = {
  			method: 'HEAD'
  		};
  		return fetch(url, opts).then(res => {
  			expect(res.status).to.equal(200);
  			expect(res.ok).to.be.true;
  		});
  	});
  
  	// issue #414
  	it('should reject if attempt to accumulate body stream throws', function () {
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  		const res = new Response(body);
  		const bufferConcat = Buffer.concat;
  		const restoreBufferConcat = () => Buffer.concat = bufferConcat;
  		Buffer.concat = () => { throw new Error('embedded error'); };
  
  		const textPromise = res.text();
  		// Ensure that `Buffer.concat` is always restored:
  		textPromise.then(restoreBufferConcat, restoreBufferConcat);
  
  		return expect(textPromise).to.eventually.be.rejected
  			.and.be.an.instanceOf(FetchError)
  			.and.include({ type: 'system' })
  			.and.have.property('message').that.includes('Could not create Buffer')
  			.and.that.includes('embedded error');
  	});
  
  	it("supports supplying a lookup function to the agent", function() {
  		const url = `${base}redirect/301`;
  		let called = 0;
  		function lookupSpy(hostname, options, callback) {
  			called++;
  			return lookup(hostname, options, callback);
  		}
  		const agent = http.Agent({ lookup: lookupSpy });
  		return fetch(url, { agent }).then(() => {
  			expect(called).to.equal(2);
  		});
  	});
  
  	it("supports supplying a famliy option to the agent", function() {
  		const url = `${base}redirect/301`;
  		const families = [];
  		const family = Symbol('family');
  		function lookupSpy(hostname, options, callback) {
  			families.push(options.family)
  			return lookup(hostname, {}, callback);
  		}
  		const agent = http.Agent({ lookup: lookupSpy, family });
  		return fetch(url, { agent }).then(() => {
  			expect(families).to.have.length(2);
  			expect(families[0]).to.equal(family);
  			expect(families[1]).to.equal(family);
  		});
  	});
  });
  
  describe('Headers', function () {
  	it('should have attributes conforming to Web IDL', function () {
  		const headers = new Headers();
  		expect(Object.getOwnPropertyNames(headers)).to.be.empty;
  		const enumerableProperties = [];
  		for (const property in headers) {
  			enumerableProperties.push(property);
  		}
  		for (const toCheck of [
  			'append', 'delete', 'entries', 'forEach', 'get', 'has', 'keys', 'set',
  			'values'
  		]) {
  			expect(enumerableProperties).to.contain(toCheck);
  		}
  	});
  
  	it('should allow iterating through all headers with forEach', function() {
  		const headers = new Headers([
  			['b', '2'],
  			['c', '4'],
  			['b', '3'],
  			['a', '1']
  		]);
  		expect(headers).to.have.property('forEach');
  
  		const result = [];
  		headers.forEach((val, key) => {
  			result.push([key, val]);
  		});
  
  		expect(result).to.deep.equal([
  			["a", "1"],
  			["b", "2, 3"],
  			["c", "4"]
  		]);
  	});
  
  	it('should allow iterating through all headers with for-of loop', function() {
  		const headers = new Headers([
  			['b', '2'],
  			['c', '4'],
  			['a', '1']
  		]);
  		headers.append('b', '3');
  		expect(headers).to.be.iterable;
  
  		const result = [];
  		for (let pair of headers) {
  			result.push(pair);
  		}
  		expect(result).to.deep.equal([
  			['a', '1'],
  			['b', '2, 3'],
  			['c', '4']
  		]);
  	});
  
  	it('should allow iterating through all headers with entries()', function() {
  		const headers = new Headers([
  			['b', '2'],
  			['c', '4'],
  			['a', '1']
  		]);
  		headers.append('b', '3');
  
  		expect(headers.entries()).to.be.iterable
  			.and.to.deep.iterate.over([
  				['a', '1'],
  				['b', '2, 3'],
  				['c', '4']
  			]);
  	});
  
  	it('should allow iterating through all headers with keys()', function() {
  		const headers = new Headers([
  			['b', '2'],
  			['c', '4'],
  			['a', '1']
  		]);
  		headers.append('b', '3');
  
  		expect(headers.keys()).to.be.iterable
  			.and.to.iterate.over(['a', 'b', 'c']);
  	});
  
  	it('should allow iterating through all headers with values()', function() {
  		const headers = new Headers([
  			['b', '2'],
  			['c', '4'],
  			['a', '1']
  		]);
  		headers.append('b', '3');
  
  		expect(headers.values()).to.be.iterable
  			.and.to.iterate.over(['1', '2, 3', '4']);
  	});
  
  	it('should reject illegal header', function() {
  		const headers = new Headers();
  		expect(() => new Headers({ 'He y': 'ok' })).to.throw(TypeError);
  		expect(() => new Headers({ 'Hé-y': 'ok' })).to.throw(TypeError);
  		expect(() => new Headers({ 'He-y': 'ăk' })).to.throw(TypeError);
  		expect(() => headers.append('Hé-y', 'ok')) .to.throw(TypeError);
  		expect(() => headers.delete('Hé-y'))       .to.throw(TypeError);
  		expect(() => headers.get('Hé-y'))          .to.throw(TypeError);
  		expect(() => headers.has('Hé-y'))          .to.throw(TypeError);
  		expect(() => headers.set('Hé-y', 'ok'))    .to.throw(TypeError);
  		// should reject empty header
  		expect(() => headers.append('', 'ok'))     .to.throw(TypeError);
  
  		// 'o k' is valid value but invalid name
  		new Headers({ 'He-y': 'o k' });
  	});
  
  	it('should ignore unsupported attributes while reading headers', function() {
  		const FakeHeader = function () {};
  		// prototypes are currently ignored
  		// This might change in the future: #181
  		FakeHeader.prototype.z = 'fake';
  
  		const res = new FakeHeader;
  		res.a = 'string';
  		res.b = ['1','2'];
  		res.c = '';
  		res.d = [];
  		res.e = 1;
  		res.f = [1, 2];
  		res.g = { a:1 };
  		res.h = undefined;
  		res.i = null;
  		res.j = NaN;
  		res.k = true;
  		res.l = false;
  		res.m = Buffer.from('test');
  
  		const h1 = new Headers(res);
  		h1.set('n', [1, 2]);
  		h1.append('n', ['3', 4])
  
  		const h1Raw = h1.raw();
  
  		expect(h1Raw['a']).to.include('string');
  		expect(h1Raw['b']).to.include('1,2');
  		expect(h1Raw['c']).to.include('');
  		expect(h1Raw['d']).to.include('');
  		expect(h1Raw['e']).to.include('1');
  		expect(h1Raw['f']).to.include('1,2');
  		expect(h1Raw['g']).to.include('[object Object]');
  		expect(h1Raw['h']).to.include('undefined');
  		expect(h1Raw['i']).to.include('null');
  		expect(h1Raw['j']).to.include('NaN');
  		expect(h1Raw['k']).to.include('true');
  		expect(h1Raw['l']).to.include('false');
  		expect(h1Raw['m']).to.include('test');
  		expect(h1Raw['n']).to.include('1,2');
  		expect(h1Raw['n']).to.include('3,4');
  
  		expect(h1Raw['z']).to.be.undefined;
  	});
  
  	it('should wrap headers', function() {
  		const h1 = new Headers({
  			a: '1'
  		});
  		const h1Raw = h1.raw();
  
  		const h2 = new Headers(h1);
  		h2.set('b', '1');
  		const h2Raw = h2.raw();
  
  		const h3 = new Headers(h2);
  		h3.append('a', '2');
  		const h3Raw = h3.raw();
  
  		expect(h1Raw['a']).to.include('1');
  		expect(h1Raw['a']).to.not.include('2');
  
  		expect(h2Raw['a']).to.include('1');
  		expect(h2Raw['a']).to.not.include('2');
  		expect(h2Raw['b']).to.include('1');
  
  		expect(h3Raw['a']).to.include('1');
  		expect(h3Raw['a']).to.include('2');
  		expect(h3Raw['b']).to.include('1');
  	});
  
  	it('should accept headers as an iterable of tuples', function() {
  		let headers;
  
  		headers = new Headers([
  			['a', '1'],
  			['b', '2'],
  			['a', '3']
  		]);
  		expect(headers.get('a')).to.equal('1, 3');
  		expect(headers.get('b')).to.equal('2');
  
  		headers = new Headers([
  			new Set(['a', '1']),
  			['b', '2'],
  			new Map([['a', null], ['3', null]]).keys()
  		]);
  		expect(headers.get('a')).to.equal('1, 3');
  		expect(headers.get('b')).to.equal('2');
  
  		headers = new Headers(new Map([
  			['a', '1'],
  			['b', '2']
  		]));
  		expect(headers.get('a')).to.equal('1');
  		expect(headers.get('b')).to.equal('2');
  	});
  
  	it('should throw a TypeError if non-tuple exists in a headers initializer', function() {
  		expect(() => new Headers([ ['b', '2', 'huh?'] ])).to.throw(TypeError);
  		expect(() => new Headers([ 'b2' ])).to.throw(TypeError);
  		expect(() => new Headers('b2')).to.throw(TypeError);
  		expect(() => new Headers({ [Symbol.iterator]: 42 })).to.throw(TypeError);
  	});
  });
  
  describe('Response', function () {
  	it('should have attributes conforming to Web IDL', function () {
  		const res = new Response();
  		const enumerableProperties = [];
  		for (const property in res) {
  			enumerableProperties.push(property);
  		}
  		for (const toCheck of [
  			'body', 'bodyUsed', 'arrayBuffer', 'blob', 'json', 'text',
  			'url', 'status', 'ok', 'statusText', 'headers', 'clone'
  		]) {
  			expect(enumerableProperties).to.contain(toCheck);
  		}
  		for (const toCheck of [
  			'body', 'bodyUsed', 'url', 'status', 'ok', 'statusText',
  			'headers'
  		]) {
  			expect(() => {
  				res[toCheck] = 'abc';
  			}).to.throw();
  		}
  	});
  
  	it('should support empty options', function() {
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  		const res = new Response(body);
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support parsing headers', function() {
  		const res = new Response(null, {
  			headers: {
  				a: '1'
  			}
  		});
  		expect(res.headers.get('a')).to.equal('1');
  	});
  
  	it('should support text() method', function() {
  		const res = new Response('a=1');
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support json() method', function() {
  		const res = new Response('{"a":1}');
  		return res.json().then(result => {
  			expect(result.a).to.equal(1);
  		});
  	});
  
  	it('should support buffer() method', function() {
  		const res = new Response('a=1');
  		return res.buffer().then(result => {
  			expect(result.toString()).to.equal('a=1');
  		});
  	});
  
  	it('should support blob() method', function() {
  		const res = new Response('a=1', {
  			method: 'POST',
  			headers: {
  				'Content-Type': 'text/plain'
  			}
  		});
  		return res.blob().then(function(result) {
  			expect(result).to.be.an.instanceOf(Blob);
  			expect(result.size).to.equal(3);
  			expect(result.type).to.equal('text/plain');
  		});
  	});
  
  	it('should support clone() method', function() {
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  		const res = new Response(body, {
  			headers: {
  				a: '1'
  			},
  			url: base,
  			status: 346,
  			statusText: 'production'
  		});
  		const cl = res.clone();
  		expect(cl.headers.get('a')).to.equal('1');
  		expect(cl.url).to.equal(base);
  		expect(cl.status).to.equal(346);
  		expect(cl.statusText).to.equal('production');
  		expect(cl.ok).to.be.false;
  		// clone body shouldn't be the same body
  		expect(cl.body).to.not.equal(body);
  		return cl.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support stream as body', function() {
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  		const res = new Response(body);
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support string as body', function() {
  		const res = new Response('a=1');
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support buffer as body', function() {
  		const res = new Response(Buffer.from('a=1'));
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support ArrayBuffer as body', function() {
  		const res = new Response(stringToArrayBuffer('a=1'));
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support blob as body', function() {
  		const res = new Response(new Blob(['a=1']));
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support Uint8Array as body', function() {
  		const res = new Response(new Uint8Array(stringToArrayBuffer('a=1')));
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support DataView as body', function() {
  		const res = new Response(new DataView(stringToArrayBuffer('a=1')));
  		return res.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should default to null as body', function() {
  		const res = new Response();
  		expect(res.body).to.equal(null);
  
  		return res.text().then(result => expect(result).to.equal(''));
  	});
  
  	it('should default to 200 as status code', function() {
  		const res = new Response(null);
  		expect(res.status).to.equal(200);
  	});
  });
  
  describe('Request', function () {
  	it('should have attributes conforming to Web IDL', function () {
  		const req = new Request('https://github.com/');
  		const enumerableProperties = [];
  		for (const property in req) {
  			enumerableProperties.push(property);
  		}
  		for (const toCheck of [
  			'body', 'bodyUsed', 'arrayBuffer', 'blob', 'json', 'text',
  			'method', 'url', 'headers', 'redirect', 'clone', 'signal',
  		]) {
  			expect(enumerableProperties).to.contain(toCheck);
  		}
  		for (const toCheck of [
  			'body', 'bodyUsed', 'method', 'url', 'headers', 'redirect', 'signal',
  		]) {
  			expect(() => {
  				req[toCheck] = 'abc';
  			}).to.throw();
  		}
  	});
  
  	it('should support wrapping Request instance', function() {
  		const url = `${base}hello`;
  
  		const form = new FormData();
  		form.append('a', '1');
  		const { signal } = new AbortController();
  
  		const r1 = new Request(url, {
  			method: 'POST',
  			follow: 1,
  			body: form,
  			signal,
  		});
  		const r2 = new Request(r1, {
  			follow: 2
  		});
  
  		expect(r2.url).to.equal(url);
  		expect(r2.method).to.equal('POST');
  		expect(r2.signal).to.equal(signal);
  		// note that we didn't clone the body
  		expect(r2.body).to.equal(form);
  		expect(r1.follow).to.equal(1);
  		expect(r2.follow).to.equal(2);
  		expect(r1.counter).to.equal(0);
  		expect(r2.counter).to.equal(0);
  	});
  
  	it('should override signal on derived Request instances', function() {
  		const parentAbortController = new AbortController();
  		const derivedAbortController = new AbortController();
  		const parentRequest = new Request(`test`, {
  			signal: parentAbortController.signal
  		});
  		const derivedRequest = new Request(parentRequest, {
  			signal: derivedAbortController.signal
  		});
  		expect(parentRequest.signal).to.equal(parentAbortController.signal);
  		expect(derivedRequest.signal).to.equal(derivedAbortController.signal);
  	});
  
  	it('should allow removing signal on derived Request instances', function() {
  		const parentAbortController = new AbortController();
  		const parentRequest = new Request(`test`, {
  			signal: parentAbortController.signal
  		});
  		const derivedRequest = new Request(parentRequest, {
  			signal: null
  		});
  		expect(parentRequest.signal).to.equal(parentAbortController.signal);
  		expect(derivedRequest.signal).to.equal(null);
  	});
  
  	it('should throw error with GET/HEAD requests with body', function() {
  		expect(() => new Request('.', { body: '' }))
  			.to.throw(TypeError);
  		expect(() => new Request('.', { body: 'a' }))
  			.to.throw(TypeError);
  		expect(() => new Request('.', { body: '', method: 'HEAD' }))
  			.to.throw(TypeError);
  		expect(() => new Request('.', { body: 'a', method: 'HEAD' }))
  			.to.throw(TypeError);
  		expect(() => new Request('.', { body: 'a', method: 'get' }))
  			.to.throw(TypeError);
  		expect(() => new Request('.', { body: 'a', method: 'head' }))
  			.to.throw(TypeError);
  	});
  
  	it('should default to null as body', function() {
  		const req = new Request('.');
  		expect(req.body).to.equal(null);
  		return req.text().then(result => expect(result).to.equal(''));
  	});
  
  	it('should support parsing headers', function() {
  		const url = base;
  		const req = new Request(url, {
  			headers: {
  				a: '1'
  			}
  		});
  		expect(req.url).to.equal(url);
  		expect(req.headers.get('a')).to.equal('1');
  	});
  
  	it('should support arrayBuffer() method', function() {
  		const url = base;
  		var req = new Request(url, {
  			method: 'POST',
  			body: 'a=1'
  		});
  		expect(req.url).to.equal(url);
  		return req.arrayBuffer().then(function(result) {
  			expect(result).to.be.an.instanceOf(ArrayBuffer);
  			const str = String.fromCharCode.apply(null, new Uint8Array(result));
  			expect(str).to.equal('a=1');
  		});
  	});
  
  	it('should support text() method', function() {
  		const url = base;
  		const req = new Request(url, {
  			method: 'POST',
  			body: 'a=1'
  		});
  		expect(req.url).to.equal(url);
  		return req.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support json() method', function() {
  		const url = base;
  		const req = new Request(url, {
  			method: 'POST',
  			body: '{"a":1}'
  		});
  		expect(req.url).to.equal(url);
  		return req.json().then(result => {
  			expect(result.a).to.equal(1);
  		});
  	});
  
  	it('should support buffer() method', function() {
  		const url = base;
  		const req = new Request(url, {
  			method: 'POST',
  			body: 'a=1'
  		});
  		expect(req.url).to.equal(url);
  		return req.buffer().then(result => {
  			expect(result.toString()).to.equal('a=1');
  		});
  	});
  
  	it('should support blob() method', function() {
  		const url = base;
  		var req = new Request(url, {
  			method: 'POST',
  			body: Buffer.from('a=1')
  		});
  		expect(req.url).to.equal(url);
  		return req.blob().then(function(result) {
  			expect(result).to.be.an.instanceOf(Blob);
  			expect(result.size).to.equal(3);
  			expect(result.type).to.equal('');
  		});
  	});
  
  	it('should support arbitrary url', function() {
  		const url = 'anything';
  		const req = new Request(url);
  		expect(req.url).to.equal('anything');
  	});
  
  	it('should support clone() method', function() {
  		const url = base;
  		let body = resumer().queue('a=1').end();
  		body = body.pipe(new stream.PassThrough());
  		const agent = new http.Agent();
  		const { signal } = new AbortController();
  		const req = new Request(url, {
  			body,
  			method: 'POST',
  			redirect: 'manual',
  			headers: {
  				b: '2'
  			},
  			follow: 3,
  			compress: false,
  			agent,
  			signal,
  		});
  		const cl = req.clone();
  		expect(cl.url).to.equal(url);
  		expect(cl.method).to.equal('POST');
  		expect(cl.redirect).to.equal('manual');
  		expect(cl.headers.get('b')).to.equal('2');
  		expect(cl.follow).to.equal(3);
  		expect(cl.compress).to.equal(false);
  		expect(cl.method).to.equal('POST');
  		expect(cl.counter).to.equal(0);
  		expect(cl.agent).to.equal(agent);
  		expect(cl.signal).to.equal(signal);
  		// clone body shouldn't be the same body
  		expect(cl.body).to.not.equal(body);
  		return Promise.all([cl.text(), req.text()]).then(results => {
  			expect(results[0]).to.equal('a=1');
  			expect(results[1]).to.equal('a=1');
  		});
  	});
  
  	it('should support ArrayBuffer as body', function() {
  		const req = new Request('', {
  			method: 'POST',
  			body: stringToArrayBuffer('a=1')
  		});
  		return req.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support Uint8Array as body', function() {
  		const req = new Request('', {
  			method: 'POST',
  			body: new Uint8Array(stringToArrayBuffer('a=1'))
  		});
  		return req.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  
  	it('should support DataView as body', function() {
  		const req = new Request('', {
  			method: 'POST',
  			body: new DataView(stringToArrayBuffer('a=1'))
  		});
  		return req.text().then(result => {
  			expect(result).to.equal('a=1');
  		});
  	});
  });
  
  function streamToPromise(stream, dataHandler) {
  	return new Promise((resolve, reject) => {
  		stream.on('data', (...args) => {
  			Promise.resolve()
  				.then(() => dataHandler(...args))
  				.catch(reject);
  		});
  		stream.on('end', resolve);
  		stream.on('error', reject);
  	});
  }
  
  describe('external encoding', () => {
  	const hasEncoding = typeof convert === 'function';
  
  	describe('with optional `encoding`', function() {
  		before(function() {
  			if(!hasEncoding) this.skip();
  		});
  
  		it('should only use UTF-8 decoding with text()', function() {
  			const url = `${base}encoding/euc-jp`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.text().then(result => {
  					expect(result).to.equal('<?xml version="1.0" encoding="EUC-JP"?><title>\ufffd\ufffd\ufffd\u0738\ufffd</title>');
  				});
  			});
  		});
  
  		it('should support encoding decode, xml dtd detect', function() {
  			const url = `${base}encoding/euc-jp`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('<?xml version="1.0" encoding="EUC-JP"?><title>日本語</title>');
  				});
  			});
  		});
  
  		it('should support encoding decode, content-type detect', function() {
  			const url = `${base}encoding/shift-jis`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('<div>日本語</div>');
  				});
  			});
  		});
  
  		it('should support encoding decode, html5 detect', function() {
  			const url = `${base}encoding/gbk`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('<meta charset="gbk"><div>中文</div>');
  				});
  			});
  		});
  
  		it('should support encoding decode, html4 detect', function() {
  			const url = `${base}encoding/gb2312`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('<meta http-equiv="Content-Type" content="text/html; charset=gb2312"><div>中文</div>');
  				});
  			});
  		});
  
  		it('should default to utf8 encoding', function() {
  			const url = `${base}encoding/utf8`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				expect(res.headers.get('content-type')).to.be.null;
  				return res.textConverted().then(result => {
  					expect(result).to.equal('中文');
  				});
  			});
  		});
  
  		it('should support uncommon content-type order, charset in front', function() {
  			const url = `${base}encoding/order1`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('中文');
  				});
  			});
  		});
  
  		it('should support uncommon content-type order, end with qs', function() {
  			const url = `${base}encoding/order2`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				return res.textConverted().then(result => {
  					expect(result).to.equal('中文');
  				});
  			});
  		});
  
  		it('should support chunked encoding, html4 detect', function() {
  			const url = `${base}encoding/chunked`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				const padding = 'a'.repeat(10);
  				return res.textConverted().then(result => {
  					expect(result).to.equal(`${padding}<meta http-equiv="Content-Type" content="text/html; charset=Shift_JIS" /><div>日本語</div>`);
  				});
  			});
  		});
  
  		it('should only do encoding detection up to 1024 bytes', function() {
  			const url = `${base}encoding/invalid`;
  			return fetch(url).then(res => {
  				expect(res.status).to.equal(200);
  				const padding = 'a'.repeat(1200);
  				return res.textConverted().then(result => {
  					expect(result).to.not.equal(`${padding}中文`);
  				});
  			});
  		});
  	});
  
  	describe('without optional `encoding`', function() {
  		before(function() {
  			if (hasEncoding) this.skip()
  		});
  
  		it('should throw a FetchError if res.textConverted() is called without `encoding` in require cache', () => {
  			const url = `${base}hello`;
  			return fetch(url).then((res) => {
  				return expect(res.textConverted()).to.eventually.be.rejected
  					.and.have.property('message').which.includes('encoding')
  			});
  		});
  	});
  });
  