activemodel/lib/active_model/type/integer.rb


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# frozen_string_literal: true

module ActiveModel
  module Type
    class Integer < Value # :nodoc:
      include Helpers::Numeric

      # Column storage size in bytes.
      # 4 bytes means an integer as opposed to smallint etc.
      DEFAULT_LIMIT = 4

      def initialize(*)
        super
        @range = min_value...max_value
      end

      def type
        :integer
      end

      def serialize(value)
        result = super
        if result
          ensure_in_range(result)
        end
        result
      end

      private
        attr_reader :range

        def cast_value(value)
          value.to_i rescue nil
        end

        def ensure_in_range(value)
          unless range.cover?(value)
            raise ActiveModel::RangeError, "#{value} is out of range for #{self.class} with limit #{_limit} bytes"
          end
        end

        def max_value
          1 << (_limit * 8 - 1) # 8 bits per byte with one bit for sign
        end

        def min_value
          -max_value
        end

        def _limit
          limit || DEFAULT_LIMIT
        end
    end
  end
end