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, 3 insertions, 3 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index e975f4fbdd..7ec0dfce7a 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1315,7 +1315,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, summit.client_of
   end
 
-  def test_deleting_by_fixnum_id
+  def test_deleting_by_integer_id
     david = Developer.find(1)
 
     assert_difference 'david.projects.count', -1 do
@@ -1352,7 +1352,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, companies(:first_firm).clients_of_firm.reload.size
   end
 
-  def test_destroying_by_fixnum_id
+  def test_destroying_by_integer_id
     force_signal37_to_load_all_clients_of_firm
 
     assert_difference "Client.count", -1 do
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index c7bd9d2119..3047914b70 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -598,7 +598,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
     assert_raise(ActiveRecord::AssociationTypeMismatch) { posts(:thinking).tags.delete(Object.new) }
   end
 
-  def test_deleting_by_fixnum_id_from_has_many_through
+  def test_deleting_by_integer_id_from_has_many_through
     post = posts(:thinking)
 
     assert_difference 'post.tags.count', -1 do