Stringify an object stream into an array

stringifyIntoArray.js

var through = require('through2');

function stringifyIntoArray() {
    var isFirstElem = true;

    return through.obj(function(data, enc, next) {
        if (isFirstElem) {
            this.push('[');
            isFirstElem = false;
        } else {
            this.push(',');
        }

        this.push(JSON.stringify(data));
        next();
    }, function(next) {
        this.push(']');
        next();
    });
}

objStream.pipe(stringifyIntoArray()).pipe(res);