6 files changed, 15 insertions, 13 deletions
diff --git a/activemodel/test/cases/attribute_assignment_test.rb b/activemodel/test/cases/attribute_assignment_test.rb
index 8eb389d331..fa41d1b95f 100644
--- a/activemodel/test/cases/attribute_assignment_test.rb
+++ b/activemodel/test/cases/attribute_assignment_test.rb
@@ -16,6 +16,8 @@ class AttributeAssignmentTest < ActiveModel::TestCase
       raise ErrorFromAttributeWriter
     end
 
+    # TODO Change this to private once we've dropped Ruby 2.2 support.
+    # Workaround for Ruby 2.2 "private attribute?" warning.
     protected
 
       attr_writer :metadata
diff --git a/activemodel/test/cases/secure_password_test.rb b/activemodel/test/cases/secure_password_test.rb
index 9423df2c09..77ce86f392 100644
--- a/activemodel/test/cases/secure_password_test.rb
+++ b/activemodel/test/cases/secure_password_test.rb
@@ -179,7 +179,7 @@ class SecurePasswordTest < ActiveModel::TestCase
 
   test "setting a nil password should clear an existing password" do
     @existing_user.password = nil
-    assert_equal nil, @existing_user.password_digest
+    assert_nil @existing_user.password_digest
   end
 
   test "authenticate" do
diff --git a/activemodel/test/cases/type/binary_test.rb b/activemodel/test/cases/type/binary_test.rb
index e6a32dbeec..e9c2ccfca4 100644
--- a/activemodel/test/cases/type/binary_test.rb
+++ b/activemodel/test/cases/type/binary_test.rb
@@ -6,7 +6,7 @@ module ActiveModel
     class BinaryTest < ActiveModel::TestCase
       def test_type_cast_binary
         type = Type::Binary.new
-        assert_equal nil, type.cast(nil)
+        assert_nil type.cast(nil)
         assert_equal "1", type.cast("1")
         assert_equal 1, type.cast(1)
       end
diff --git a/activemodel/test/cases/type/date_test.rb b/activemodel/test/cases/type/date_test.rb
index 44e20a327b..0cc90e99d3 100644
--- a/activemodel/test/cases/type/date_test.rb
+++ b/activemodel/test/cases/type/date_test.rb
@@ -6,10 +6,10 @@ module ActiveModel
     class DateTest < ActiveModel::TestCase
       def test_type_cast_date
         type = Type::Date.new
-        assert_equal nil, type.cast(nil)
-        assert_equal nil, type.cast("")
-        assert_equal nil, type.cast(" ")
-        assert_equal nil, type.cast("ABC")
+        assert_nil type.cast(nil)
+        assert_nil type.cast("")
+        assert_nil type.cast(" ")
+        assert_nil type.cast("ABC")
 
         date_string = ::Time.now.utc.strftime("%F")
         assert_equal date_string, type.cast(date_string).strftime("%F")
diff --git a/activemodel/test/cases/type/date_time_test.rb b/activemodel/test/cases/type/date_time_test.rb
index fb82260d2b..75a7fc686e 100644
--- a/activemodel/test/cases/type/date_time_test.rb
+++ b/activemodel/test/cases/type/date_time_test.rb
@@ -6,10 +6,10 @@ module ActiveModel
     class DateTimeTest < ActiveModel::TestCase
       def test_type_cast_datetime_and_timestamp
         type = Type::DateTime.new
-        assert_equal nil, type.cast(nil)
-        assert_equal nil, type.cast("")
-        assert_equal nil, type.cast("  ")
-        assert_equal nil, type.cast("ABC")
+        assert_nil type.cast(nil)
+        assert_nil type.cast("")
+        assert_nil type.cast("  ")
+        assert_nil type.cast("ABC")
 
         datetime_string = ::Time.now.utc.strftime("%FT%T")
         assert_equal datetime_string, type.cast(datetime_string).strftime("%FT%T")
diff --git a/activemodel/test/cases/type/time_test.rb b/activemodel/test/cases/type/time_test.rb
index a6a79833e6..0cc4d33caa 100644
--- a/activemodel/test/cases/type/time_test.rb
+++ b/activemodel/test/cases/type/time_test.rb
@@ -6,9 +6,9 @@ module ActiveModel
     class TimeTest < ActiveModel::TestCase
       def test_type_cast_time
         type = Type::Time.new
-        assert_equal nil, type.cast(nil)
-        assert_equal nil, type.cast("")
-        assert_equal nil, type.cast("ABC")
+        assert_nil type.cast(nil)
+        assert_nil type.cast("")
+        assert_nil type.cast("ABC")
 
         time_string = ::Time.now.utc.strftime("%T")
         assert_equal time_string, type.cast(time_string).strftime("%T")