How does Facebook encode emoji in the json Graph API?

Question

Does anyone know how Facebook encodes emoji with high-surrogate pairs in the Graph API?

Low surrogate pairs seem fine. For example, ❤️ (HEAVY BLACK HEART, though it

Answer 1

Answering my own question though most of the credit belongs to @bobince for showing me the way in the comments above.

The answer is that Facebook encodes emoji using the "Google" encoding as seen on this Unicode table.

I have created a ruby gem called emojivert that can convert from one encoding to another, including from "Google" to "Unified". It is based on another existing project called rails-emoji.

So the failing example above would be fixed by doing:

string = ActiveSupport::JSON.decode('"\udbba\udf59"')
> "