1 files changed, 31 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/validations/clusivity.rb b/activemodel/lib/active_model/validations/clusivity.rb
new file mode 100644
index 0000000000..b632a2bd6b
--- /dev/null
+++ b/activemodel/lib/active_model/validations/clusivity.rb
@@ -0,0 +1,31 @@
+require 'active_support/core_ext/range.rb'
+
+module ActiveModel
+  module Validations
+    module Clusivity
+      ERROR_MESSAGE = "An object with the method #include? or a proc or lambda is required, " <<
+                      "and must be supplied as the :in option of the configuration hash"
+
+      def check_validity!
+        unless [:include?, :call].any?{ |method| options[:in].respond_to?(method) }
+          raise ArgumentError, ERROR_MESSAGE
+        end
+      end
+
+    private
+
+      def include?(record, value)
+        delimiter = options[:in]
+        exclusions = delimiter.respond_to?(:call) ? delimiter.call(record) : delimiter
+        exclusions.send(inclusion_method(exclusions), value)
+      end
+
+      # In Ruby 1.9 <tt>Range#include?</tt> on non-numeric ranges checks all possible values in the
+      # range for equality, so it may be slow for large ranges. The new <tt>Range#cover?</tt>
+      # uses the previous logic of comparing a value with the range endpoints.
+      def inclusion_method(enumerable)
+        enumerable.is_a?(Range) ? :cover? : :include?
+      end
+    end
+  end
+end