devChallenge1.js

var hyperquest = require('hyperquest');

module.exports = function downloadUtf8FileIntoString(url, cb) {
	if (!url) return cb(new Error('url is required')); 
	var result = ''; // fixed scope
	hyperquest(url)
		.pipe(function (chunk, enc, tCb) { 
			result += chunk.toString('utf8');	// binary to utf8
			tCb();
		})
		.on('finish', function () {
			cb(null, result); // fixed
		})
}

There is still at least one more issue in here relating to hyperquest... Can you find it? 😄