1 files changed, 35 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/infinite_comparable.rb
new file mode 100644
index 0000000000..b78b2deaad
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/infinite_comparable.rb
@@ -0,0 +1,35 @@
+require 'active_support/concern'
+require 'active_support/core_ext/module/aliasing'
+require 'active_support/core_ext/object/try'
+
+module InfiniteComparable
+  extend ActiveSupport::Concern
+
+  included do
+    alias_method_chain :<=>, :infinity
+  end
+
+  define_method :'<=>_with_infinity' do |other|
+    if other.class == self.class
+      public_send :'<=>_without_infinity', other
+    else
+      infinite = try(:infinite?)
+      other_infinite = other.try(:infinite?)
+
+      # inf <=> inf
+      if infinite && other_infinite
+        infinite <=> other_infinite
+      # not_inf <=> inf
+      elsif other_infinite
+        -other_infinite
+      # inf <=> not_inf
+      elsif infinite
+        infinite
+      else
+        conversion = "to_#{self.class.name.downcase}"
+        other = other.public_send(conversion) if other.respond_to?(conversion)
+        public_send :'<=>_without_infinity', other
+      end
+    end
+  end
+end