Separate ::Range check from other logic

Also add specs to show the difference between `===` and `.include?`.

activesupport/lib/active_support/core_ext/range/compare_range.rb

@@ -12,7 +12,7 @@ module CompareWithRange
     #  ('a'..'f') === ('c') # => true
     #  (5..9) === (11) # => false
     def ===(other)
-      compare_with_range(other) { |arg_for_comparison| super(arg_for_comparison) }
+      compare(other) { |arg_for_comparison| super(arg_for_comparison) }
     end
 
     # Extends the default Range#include? to support range comparisons.
@@ -25,20 +25,24 @@ def ===(other)
     #  ('a'..'f').include?('c') # => true
     #  (5..9).include?(11) # => false
     def include?(other)
-      compare_with_range(other) { |arg_for_comparison| super(arg_for_comparison) }
+      compare(other) { |arg_for_comparison| super(arg_for_comparison) }
     end
 
     private
-      def compare_with_range(other, &block)
+      def compare(other, &block)
         if other.is_a?(::Range)
-          return false if other_is_backwards?(other)
-
-          begin_includes_other_begin?(other, &block) && end_includes_other_end?(other)
+          compare_with_range(other, &block)
         else
           block.call(other)
         end
       end
 
+      def compare_with_range(other, &block)
+        return false if other_is_backwards?(other)
+
+        begin_includes_other_begin?(other, &block) && end_includes_other_end?(other)
+      end
+
       def other_is_backwards?(other)
         is_backwards_op = other.exclude_end? ? :>= : :>
         other.begin && other.end && other.begin.public_send(is_backwards_op, other.end)

activesupport/test/core_ext/range_ext_test.rb

@@ -131,6 +131,13 @@ def test_overlap_behaves_like_ruby
     assert_not_operator((...3), :overlap?, (3..))
   end
 
+  def test_include_uses_ruby_include
+    assert((1..3).include?(1.5))
+    assert(("a".."d").include?("c"))
+
+    assert_not(("a".."d").include?("cc")) # As opposed to `=== 'cc'` => `true`
+  end
+
   def test_should_include_identical_inclusive
     assert((1..10).include?(1..10))
   end
@@ -183,6 +190,13 @@ def test_should_not_include_range_with_beginless_range
     assert_not((-1..1).include?(..2))
   end
 
+  def test_case_equality_uses_ruby_case_equality
+    assert((1..3) === 1.5)
+    assert(("a".."d") === "c")
+
+    assert(("a".."d") === "cc") # As opposed to `.include?('cc')` => `false`
+  end
+
   def test_should_compare_identical_inclusive
     assert((1..10) === (1..10))
   end