Bugs in "String" serialization

[Anders Rundgren]

index.js serializes 0x7f as \u007f. This incompatible with ECMAScript 2015 and forward.
index2.js doesn't properly sort a property expressed as "".

I'm BTW working on the same problem and this is what I came up with:
https://github.com/cyberphone/json-canonicalization

[Mirko Kiefer]

Thanks for raising that @cyberphone , would be great if you could reproduce that in a failing test or even contribute a PR with a fix.

[Anders Rundgren]

Hi @mirkokiefer Actually it is Crockford's json2 that is incompatible with ECMAScript 2015.
Index2 is almost right but fails on the "" edge case because ECMAScript 2015 has its own sorting rule.

This code does (AFAICT...) canonicalization in a way that is compatible with ECMAScript 2015 edition 6:

// ES6 JSON Canonicalizer
'use strict';
var canonicalize = function(object) {

    var buffer = '';
    serialize(object);
    return buffer;

    function serialize(object) {
        if (object !== null && typeof object === 'object') {
            if (Array.isArray(object)) {
                buffer += '[';
                let next = false;
                object.forEach((element) => {
                    if (next) {
                        buffer += ',';
                    }
                    next = true;
                    serialize(element);
                });
                buffer += ']';
            } else {
                buffer += '{';
                let next = false;
                Object.keys(object).sort().forEach((property) => {
                    if (next) {
                        buffer += ',';
                    }
                    next = true;
                    buffer += JSON.stringify(property);
                    buffer += ':';
                    serialize(object[property]);
                });
                buffer += '}';
            }
        } else {
            buffer += JSON.stringify(object);
        }
    }
};

module.exports = canonicalize;

I'm hoping to make this an IETF standard.