4198.js

var zlib = require('zlib')
zlib.gzip(Buffer('test'), function(err, res) {
	console.dir(res)
	var resString = res.toString()
	var resBuffer = Buffer(resString, 'binary')
	console.dir(resBuffer)
	zlib.gunzip(resBuffer, function(err, text) {
		if(err) throw err
		console.log(text.toString())
	})
})

/*
$ node 4198.js 
<Buffer 1f 8b 08 00 00 00 00 00 00 03 2b 49 2d 2e 01 00 0c 7e 7f d8 04 00 00 00>
<Buffer 1f fd 08 00 00 00 00 00 00 03 2b 49 2d 2e 01 00 0c 7e 7f fd 04 00 00 00>

Error: incorrect header check
    at Zlib._binding.onerror (zlib.js:283:17)
*/