1 files changed, 66 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/type/integer.rb b/activemodel/lib/active_model/type/integer.rb
new file mode 100644
index 0000000000..2f73ede009
--- /dev/null
+++ b/activemodel/lib/active_model/type/integer.rb
@@ -0,0 +1,66 @@
+module ActiveModel
+  module Type
+    class Integer < Value # :nodoc:
+      include Helpers::Numeric
+
+      # Column storage size in bytes.
+      # 4 bytes means a MySQL int or Postgres integer as opposed to smallint etc.
+      DEFAULT_LIMIT = 4
+
+      def initialize(*)
+        super
+        @range = min_value...max_value
+      end
+
+      def type
+        :integer
+      end
+
+      def deserialize(value)
+        return if value.nil?
+        value.to_i
+      end
+
+      def serialize(value)
+        result = cast(value)
+        if result
+          ensure_in_range(result)
+        end
+        result
+      end
+
+      protected
+
+      attr_reader :range
+
+      private
+
+      def cast_value(value)
+        case value
+        when true then 1
+        when false then 0
+        else
+          value.to_i rescue nil
+        end
+      end
+
+      def ensure_in_range(value)
+        unless range.cover?(value)
+          raise RangeError, "#{value} is out of range for #{self.class} with limit #{_limit}"
+        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
+        self.limit || DEFAULT_LIMIT
+      end
+    end
+  end
+end