Flatten a JSON object (for Slack)

flatten_json.rb

require 'json'

def flatten_hash(hash)
  hash.each_with_object({}) do |(k, v), h|
    if v.is_a? Hash
      flatten_hash(v).map { |h_k, h_v| h["#{k}.#{h_k}".to_sym] = h_v }
    else 
      h[k] = v
    end
  end
end

json_raw = %({ "user": { "id": "foo", "bar": "baz" }, "id": 123 })
json = JSON.parse json_raw
puts flatten_hash(json).to_json