JSON decode with line and column error details

require "json"

struct User
  include JSON::Serializable
  getter id : Int32
  getter name : String
end

def parse_user(body : String) : User
  User.from_json(body)
rescue ex : JSON::ParseException
  raise ArgumentError.new("invalid JSON at #{ex.line_number}:#{ex.column_number}: #{ex.message}")
rescue ex : JSON::SerializableError
  raise ArgumentError.new("invalid user shape: #{ex.message}")
end