encode.js

var utf8 = require('utf8');
var val1 = utf8.decode('\xE2\x80\x99');

const StringDecoder = require('string_decoder').StringDecoder;
const decoder = new StringDecoder('utf8');

const symbol = new Buffer([0xE2, 0x80, 0x99]);
const val2 = decoder.write(symbol);

console.log(val1);
console.log(val2);
console.log(val1 === val2);