Second attempt at conditional gzip decoding based on the Content-Encoding response header with the mikeal/request library for Node.js. This DOES work.

gzipRequestTest.js

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

var headers = {
  "accept-charset" : "ISO-8859-1,utf-8;q=0.7,*;q=0.3",
  "accept-language" : "en-US,en;q=0.8",
  "accept" : "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
  "user-agent" : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.13+ (KHTML, like Gecko) Version/5.1.7 Safari/534.57.2",
  "accept-encoding" : "gzip,deflate",
};

var options = {
  url: "http://google.com",
  headers: headers
};

var requestWithEncoding = function(options, callback) {
  var req = request.get(options);

  req.on('response', function(res) {
    var chunks = [];
    res.on('data', function(chunk) {
      chunks.push(chunk);
    });

    res.on('end', function() {
      var buffer = Buffer.concat(chunks);
      var encoding = res.headers['content-encoding'];
      if (encoding == 'gzip') {
        zlib.gunzip(buffer, function(err, decoded) {
          callback(err, decoded && decoded.toString());
        });
      } else if (encoding == 'deflate') {
        zlib.inflate(buffer, function(err, decoded) {
          callback(err, decoded && decoded.toString());
        })
      } else {
        callback(null, buffer.toString());
      }
    });
  });

  req.on('error', function(err) {
    callback(err);
  });
}

requestWithEncoding(options, function(err, data) {
  if (err) console.log(err);
  else console.log(data);
})

Yes, this is working like a charm, thanks!

Still works like a charm.

In case anyone would like to make it better: the callback function could have the same request parameters (error, response, body), with the body one deflated.

and still works like a charm

Helped me, thanks! To support deflate content encoding, change inflate to inflateRaw.

great :)

非常感谢,已经学习到~(≧▽≦)/~啦啦啦....Thank you very much, has been learning to \ ^ _ ^/ La La La. ..