safeStringify.js

(function (root) {
    root.stringifySafe = stringify;
    function stringify(obj, fn, spaces, decycle) {
        return JSON.stringify(obj, getSerialize(fn, decycle), spaces);


        function getSerialize(fn, decycle) {
            var seen = [], keys = [];
            decycle = decycle || function (key, value) {
                return '[Circular ' + getPath(value, seen, keys) + ']'
            };
            return function (key, value) {
                var ret = value;
                if (typeof value === 'object' && value) {
                    if (seen.indexOf(value) !== -1)
                        ret = decycle(key, value);
                    else {
                        seen.push(value);
                        keys.push(key);
                    }
                }
                if (fn) ret = fn(key, ret);
                return ret;
            }
        }

        function getPath(value, seen, keys) {
            var index = seen.indexOf(value);
            var path = [keys[index]];
            for (index--; index >= 0; index--) {
                if (seen[index][path[0]] === value) {
                    value = seen[index];
                    path.unshift(keys[index]);
                }
            }
            return '~' + path.join('.');
        }
    }
})(JSON);