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.

9 files changed, 15 insertions, 16 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
diff --git a/activerecord/test/cases/attributes_test.rb b/activerecord/test/cases/attributes_test.rb
index 48ba7a63d5..7bcaa53aa2 100644
--- a/activerecord/test/cases/attributes_test.rb
+++ b/activerecord/test/cases/attributes_test.rb
@@ -38,7 +38,7 @@ module ActiveRecord
       data.reload
 
       assert_equal 2, data.overloaded_float
-      assert_kind_of Fixnum, OverloadedType.last.overloaded_float
+      assert_kind_of Integer, OverloadedType.last.overloaded_float
       assert_equal 2.0, UnoverloadedType.last.overloaded_float
       assert_kind_of Float, UnoverloadedType.last.overloaded_float
     end
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index eef2d29d02..3191393a41 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -940,7 +940,7 @@ class BasicsTest < ActiveRecord::TestCase
     assert_kind_of Integer, m1.world_population
     assert_equal 6000000000, m1.world_population
 
-    assert_kind_of Fixnum, m1.my_house_population
+    assert_kind_of Integer, m1.my_house_population
     assert_equal 3, m1.my_house_population
 
     assert_kind_of BigDecimal, m1.bank_balance
@@ -968,7 +968,7 @@ class BasicsTest < ActiveRecord::TestCase
     assert_kind_of Integer, m1.world_population
     assert_equal 6000000000, m1.world_population
 
-    assert_kind_of Fixnum, m1.my_house_population
+    assert_kind_of Integer, m1.my_house_population
     assert_equal 3, m1.my_house_population
 
     assert_kind_of BigDecimal, m1.bank_balance
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index da934ab8fe..9455d4886c 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -857,7 +857,7 @@ class FoxyFixturesTest < ActiveRecord::TestCase
     assert_equal("X marks the spot!", pirates(:mark).catchphrase)
   end
 
-  def test_supports_label_interpolation_for_fixnum_label
+  def test_supports_label_interpolation_for_integer_label
     assert_equal("#1 pirate!", pirates(1).catchphrase)
   end
 
diff --git a/activerecord/test/cases/migration/column_attributes_test.rb b/activerecord/test/cases/migration/column_attributes_test.rb
index c7a1b81a75..29546525f3 100644
--- a/activerecord/test/cases/migration/column_attributes_test.rb
+++ b/activerecord/test/cases/migration/column_attributes_test.rb
@@ -154,7 +154,7 @@ module ActiveRecord
           assert_equal String, bob.first_name.class
           assert_equal String, bob.last_name.class
           assert_equal String, bob.bio.class
-          assert_equal Fixnum, bob.age.class
+          assert_kind_of Integer, bob.age
           assert_equal Time, bob.birthday.class
 
           if current_adapter?(:OracleAdapter)
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index a4b0de3f4e..6ad028d31b 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -180,7 +180,7 @@ class MigrationTest < ActiveRecord::TestCase
     # is_a?(Bignum)
     assert_kind_of Integer, b.world_population
     assert_equal 6000000000, b.world_population
-    assert_kind_of Fixnum, b.my_house_population
+    assert_kind_of Integer, b.my_house_population
     assert_equal 3, b.my_house_population
     assert_kind_of BigDecimal, b.bank_balance
     assert_equal BigDecimal("1586.43"), b.bank_balance
@@ -204,7 +204,7 @@ class MigrationTest < ActiveRecord::TestCase
       assert_in_delta BigDecimal("2.71828182845905"), b.value_of_e, 0.00000000000001
     else
       # - SQL standard is an integer
-      assert_kind_of Fixnum, b.value_of_e
+      assert_kind_of Integer, b.value_of_e
       assert_equal 2, b.value_of_e
     end
 
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index e53239cdee..406643d6fb 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -144,13 +144,12 @@ class QueryCacheTest < ActiveRecord::TestCase
 
   def test_cache_does_not_wrap_string_results_in_arrays
     Task.cache do
-      # Oracle adapter returns count() as Fixnum or Float
+      # Oracle adapter returns count() as Integer or Float
       if current_adapter?(:OracleAdapter)
         assert_kind_of Numeric, Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
       elsif current_adapter?(:SQLite3Adapter, :Mysql2Adapter, :PostgreSQLAdapter)
         # Future versions of the sqlite3 adapter will return numeric
-        assert_instance_of Fixnum,
-         Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
+        assert_instance_of Fixnum, Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
       else
         assert_instance_of String, Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
       end
diff --git a/activerecord/test/cases/quoting_test.rb b/activerecord/test/cases/quoting_test.rb
index 6d91f96bf6..c01c82f4f5 100644
--- a/activerecord/test/cases/quoting_test.rb
+++ b/activerecord/test/cases/quoting_test.rb
@@ -102,9 +102,9 @@ module ActiveRecord
         assert_equal float.to_s, @quoter.quote(float, nil)
       end
 
-      def test_quote_fixnum
-        fixnum = 1
-        assert_equal fixnum.to_s, @quoter.quote(fixnum, nil)
+      def test_quote_integer
+        integer = 1
+        assert_equal integer.to_s, @quoter.quote(integer, nil)
       end
 
       def test_quote_bignum