Remove Object#__sortable__ monkey patch, which is only used in Contex…

…tual::Memory. Its been moved to private method with a minor amount of refactoring. Existing tests already cover all the functionality.

lib/mongoid/contextual/memory.rb

@@ -627,22 +627,42 @@ def apply_sorting
         end
       end
 
-      # Compare two values, checking for nil.
+      # Compare two values, handling the cases when
+      # either value is nil.
       #
       # @api private
       #
       # @example Compare the two objects.
       #   context.compare(a, b)
       #
       # @param [ Object ] a The first object.
-      # @param [ Object ] b The first object.
+      # @param [ Object ] b The second object.
       #
       # @return [ Integer ] The comparison value.
       def compare(a, b)
-        case
-        when a.nil? then b.nil? ? 0 : 1
-        when b.nil? then -1
-        else a <=> b
+        return 0 if a.nil? && b.nil?
+        return 1 if a.nil?
+        return -1 if b.nil?
+
+        compare_operand(a) <=> compare_operand(b)
+      end
+
+      # Get the operand value to be used in comparison.
+      # Adds capability to sort boolean values.
+      #
+      # @api private
+      #
+      # @example Get the comparison operand.
+      #   compare_operand(true) #=> 1
+      #
+      # @param [ Object ] value The value to be used in comparison.
+      #
+      # @return [ Integer | Object ] The comparison operand.
+      def compare_operand(value)
+        case value
+        when TrueClass then 1
+        when FalseClass then 0
+        else value
         end
       end
 
@@ -655,9 +675,8 @@ def compare(a, b)
       def in_place_sort(values)
         documents.sort! do |a, b|
           values.map do |field, direction|
-            a_value, b_value = a[field], b[field]
-            direction * compare(a_value.__sortable__, b_value.__sortable__)
-          end.find { |value| !value.zero? } || 0
+            direction * compare(a[field], b[field])
+          end.detect { |value| !value.zero? } || 0
         end
       end
 

lib/mongoid/extensions/false_class.rb

@@ -7,16 +7,6 @@ module Extensions
     # Adds type-casting behavior to FalseClass.
     module FalseClass
 
-      # Get the value of the object as a mongo friendly sort value.
-      #
-      # @example Get the object as sort criteria.
-      #   object.__sortable__
-      #
-      # @return [ Integer ] 0.
-      def __sortable__
-        0
-      end
-
       # Is the passed value a boolean?
       #
       # @example Is the value a boolean type?

lib/mongoid/extensions/object.rb

@@ -54,16 +54,6 @@ def __setter__
         "#{self}="
       end
 
-      # Get the value of the object as a mongo friendly sort value.
-      #
-      # @example Get the object as sort criteria.
-      #   object.__sortable__
-      #
-      # @return [ Object ] self.
-      def __sortable__
-        self
-      end
-
       # Conversion of an object to an $inc-able value.
       #
       # @example Convert the object.

lib/mongoid/extensions/true_class.rb

@@ -7,16 +7,6 @@ module Extensions
     # Adds type-casting behavior to TrueClass
     module TrueClass
 
-      # Get the value of the object as a mongo friendly sort value.
-      #
-      # @example Get the object as sort criteria.
-      #   object.__sortable__
-      #
-      # @return [ Integer ] 1.
-      def __sortable__
-        1
-      end
-
       # Is the passed value a boolean?
       #
       # @example Is the value a boolean type?

spec/mongoid/extensions/false_class_spec.rb

@@ -5,13 +5,6 @@
 
 describe Mongoid::Extensions::FalseClass do
 
-  describe "#__sortable__" do
-
-    it "returns 0" do
-      expect(false.__sortable__).to eq(0)
-    end
-  end
-
   describe "#is_a?" do
 
     context "when provided a Boolean" do

spec/mongoid/extensions/object_spec.rb

@@ -128,13 +128,6 @@
     end
   end
 
-  describe "#__sortable__" do
-
-    it "returns self" do
-      expect(object.__sortable__).to eq(object)
-    end
-  end
-
   describe ".demongoize" do
 
     let(:object) do

spec/mongoid/extensions/true_class_spec.rb

@@ -5,13 +5,6 @@
 
 describe Mongoid::Extensions::TrueClass do
 
-  describe "#__sortable__" do
-
-    it "returns 1" do
-      expect(true.__sortable__).to eq(1)
-    end
-  end
-
   describe "#is_a?" do
 
     context "when provided a Boolean" do