Support for unified Integer class in Ruby 2.4+

Ruby 2.4 unifies Fixnum and Bignum into Integer: https://bugs.ruby-lang.org/issues/12005

* Forward compat with new unified Integer class in Ruby 2.4+.
* Backward compat with separate Fixnum/Bignum in Ruby 2.2 & 2.3.
* Drops needless Fixnum distinction in docs, preferring Integer.

2 files changed, 6 insertions, 5 deletions

diff --git a/activesupport/test/core_ext/array/conversions_test.rb b/activesupport/test/core_ext/array/conversions_test.rb
index 507e13f968..de36e2026d 100644
--- a/activesupport/test/core_ext/array/conversions_test.rb
+++ b/activesupport/test/core_ext/array/conversions_test.rb
@@ -101,10 +101,10 @@ class ToXmlTest < ActiveSupport::TestCase
   end
 
   def test_to_xml_with_non_hash_elements
-    xml = [1, 2, 3].to_xml(skip_instruct: true, indent: 0)
+    xml = %w[1 2 3].to_xml(skip_instruct: true, indent: 0)
 
-    assert_equal '<fixnums type="array"><fixnum', xml.first(29)
-    assert xml.include?(%(<fixnum type="integer">2</fixnum>)), xml
+    assert_equal '<strings type="array"><string', xml.first(29)
+    assert xml.include?(%(<string>2</string>)), xml
   end
 
   def test_to_xml_with_non_hash_different_type_elements
diff --git a/activesupport/test/core_ext/array/grouping_test.rb b/activesupport/test/core_ext/array/grouping_test.rb
index fb7367b0bf..0682241f0b 100644
--- a/activesupport/test/core_ext/array/grouping_test.rb
+++ b/activesupport/test/core_ext/array/grouping_test.rb
@@ -3,11 +3,12 @@ require 'active_support/core_ext/array'
 
 class GroupingTest < ActiveSupport::TestCase
   def setup
-    Fixnum.send :private, :/  # test we avoid Integer#/ (redefined by mathn)
+    # In Ruby < 2.4, test we avoid Integer#/ (redefined by mathn)
+    Fixnum.send :private, :/ unless Fixnum == Integer
   end
 
   def teardown
-    Fixnum.send :public, :/
+    Fixnum.send :public, :/ unless Fixnum == Integer
   end
 
   def test_in_groups_of_with_perfect_fit