index.js

var JsFormatter = function() {

    this.spaces = "    ";
    this.new_line = "\n";

    var _this = this;

    this.format = function(data) {
        var string = '';
        try
        {
            string = iAmFormator(JSON.parse(data), 0, false);
        } catch (e) {
            string = 'Not a valid json';
        }

        return string;
    };

    function getSpacesByLevel(level) {

        var ret = '';

        for (var x = 1; x <= level; x++) {
            ret += _this.spaces;
        }
        return ret;

    }

    function iAmFormator(data, level, skip_space)
    {
        var level_space = getSpacesByLevel(level);
        var string = (skip_space ? "" : level_space) + "{" + _this.new_line;
        var iterator = 0;
        
        for (var index in data) {
            var type = typeof data[index];
            iterator++;
            switch (type) {

                case 'object':
                    if (Array.isArray(data[index])) {
                        string += getSpacesByLevel(level + 1) + '"array": [' + data[index].join(',') + ']' + (isLast(iterator, objectLength(data)) ? '' : ',') + _this.new_line;
                    } else {
                        string += getSpacesByLevel(level + 1) + '"' + index + '": ' + iAmFormator(data[index], level + 1, true) + _this.new_line;
                    }

                    break;

                case 'integer':
                case 'number':
                case 'string':
                case 'boolean':
                case 'null':
                    string += getSpacesByLevel(level + 1) + '"' + index + '": ' + printData(data[index], type) + (isLast(iterator, objectLength(data)) ? '' : ',') + _this.new_line;
                    break;
                case 'function':
                    string += getSpacesByLevel(level + 1) + '"' + index + '": function(){}' + _this.new_line;
                    break;

            }

        }
        string += level_space + "}" + _this.new_line;
        return string;
    }

    function isLast(index, length) {
        return !(index < length);
    }

    function objectLength(obj) {
        var count = 0;
        var i;

        for (i in obj) {
            if (obj.hasOwnProperty(i)) {
                count++;
            }
        }
        return count;
    }


    function printData(data, type) {

        if (type == 'string') {
            return '"' + data + '"';
        } else {
            return data;
        }

    }

};

var formattor = new JsFormatter();
module.exports = formattor;