Uncompress a HTTP response when needed

foo.js

var request = require('request');
var stream = require('stream');
var zlib = require('zlib');

var websiteRequest = request('http://oliverjash.me/', {
  headers: {
    'Accept-Encoding': 'gzip,deflate'
  }
});

// Request,  `http.ClientRequest`   – writable stream, emits a `response` event
// containing a `http.IncomingMessage`
// Response, `http.IncomingMessage` – readable stream, emits a `readable` event

websiteRequest
  .on('response', function (response) {
    // Uncompress the response (if compressed to begin with) into pipe into
    // a writable stream.

    var contentEncoding = response.headers['content-encoding'];
    var output = new stream.Writable();
    var chunks = [];
    output._write = function (chunk, enc, next) {
      chunks.push(chunk);
      next();
    };

    // TODO: Use `_.contains`
    if (['gzip', 'deflate'].indexOf(contentEncoding) !== -1) {
      response.pipe(zlib.createUnzip()).pipe(output);
    } else {
      response.pipe(output);
    }

    output
      .on('finish', function () {
        var responseBody = global.Buffer.concat(chunks).toString();
        console.log(responseBody);
      });
});