lib/formatter.js

#!/usr/bin/env node

/**
 * Manual formatter taken straight from https://github.com/umbrae/jsonlintdotcom
**/

/*jslint white: true, devel: true, onevar: true, browser: true, undef: true, nomen: true, regexp: true, plusplus: false, bitwise: true, newcap: true, maxerr: 50, indent: 4 */

/**
 * jsl.format - Provide json reformatting in a character-by-character approach, so that even invalid JSON may be reformatted (to the best of its ability).
 *
**/
var formatter = (function () {

    function repeat(s, count) {
        return new Array(count + 1).join(s);
    }

    function formatJson(json, indentChars) {
        var i           = 0,
            il          = 0,
            tab         = (typeof indentChars !== "undefined") ? indentChars : "    ",
            newJson     = "",
            indentLevel = 0,
            inString    = false,
            currentChar = null;

        for (i = 0, il = json.length; i < il; i += 1) { 
            currentChar = json.charAt(i);

            switch (currentChar) {
            case '{': 
            case '[': 
                if (!inString) { 
                    newJson += currentChar + "\n" + repeat(tab, indentLevel + 1);
                    indentLevel += 1; 
                } else { 
                    newJson += currentChar; 
                }
                break; 
            case '}': 
            case ']': 
                if (!inString) { 
                    indentLevel -= 1; 
                    newJson += "\n" + repeat(tab, indentLevel) + currentChar; 
                } else { 
                    newJson += currentChar; 
                } 
                break; 
            case ',': 
                if (!inString) { 
                    newJson += ",\n" + repeat(tab, indentLevel); 
                } else { 
                    newJson += currentChar; 
                } 
                break; 
            case ':': 
                if (!inString) { 
                    newJson += ": "; 
                } else { 
                    newJson += currentChar; 
                } 
                break; 
            case ' ':
            case "\n":
            case "\t":
                if (inString) {
                    newJson += currentChar;
                }
                break;
            case '"': 
                if (i > 0 && json.charAt(i - 1) !== '\\') {
                    inString = !inString; 
                }
                newJson += currentChar; 
                break;
            default: 
                newJson += currentChar; 
                break;                    
            } 
        } 

        return newJson; 
    }

    return { "formatJson": formatJson };

}());

if (typeof require !== 'undefined' && typeof exports !== 'undefined') {
  exports.formatter = formatter;
}