Convert value by https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.1.md#dataTypes

open_api_type_converter.rb

module OpenApiTypeConverter
  class << self
    def short(value, field_name)
      value = value.to_i
      value.bit_length > 32 ? raise(ValueIsTooLargeForInt64, field_name) : value
    end

    def long(value, field_name)
      value = value.to_i
      value.bit_length > 64 ? raise(ValueIsTooLargeForInt64, field_name) : value
    end

    def float(value, _field_name)
      value.to_f
    end

    def double(value, field_name)
      value.to_d
    end

    def string(value, field_name)
      "#{value}"
    end

    def byte(value, _field_name)
      Base64.encode64(value.to_s)
    end

    def binary(value, _field_name)
      value.to_s.bytes.map { |e| e.to_s(2) }.join(' ')
    end

    def boolean(value, _field_name)
      !!value
    end

    def date_time(value, field_name)
      prepared_val = case value
      when Integer, BigDecimal, Float
        Time.zone.at(value)
      when Date, DateTime, Time
        value
      else
        raise ValueHasIncorrectType.new("#{field_name} => #{value}")
      end
      prepared_val.rfc3339
    end

    alias int64 long
    alias int32 short
    alias date date_time
  end

  class ValueIsTooLargeForInt32 < StandardError; end
  class ValueIsTooLargeForInt64 < StandardError; end
  class ValueHasIncorrectType < StandardError; end
end