3 files changed, 16 insertions, 0 deletions
diff --git a/activesupport/test/core_ext/array/access_test.rb b/activesupport/test/core_ext/array/access_test.rb
index f14f64421d..3f1e0c4cb4 100644
--- a/activesupport/test/core_ext/array/access_test.rb
+++ b/activesupport/test/core_ext/array/access_test.rb
@@ -27,4 +27,8 @@ class AccessTest < ActiveSupport::TestCase
     assert_equal array[4], array.fifth
     assert_equal array[41], array.forty_two
   end
+
+  def test_without
+    assert_equal [1, 2, 4], [1, 2, 3, 4, 5].without(3, 5)
+  end
 end
diff --git a/activesupport/test/core_ext/array/conversions_test.rb b/activesupport/test/core_ext/array/conversions_test.rb
index 577b889410..507e13f968 100644
--- a/activesupport/test/core_ext/array/conversions_test.rb
+++ b/activesupport/test/core_ext/array/conversions_test.rb
@@ -60,6 +60,12 @@ class ToSentenceTest < ActiveSupport::TestCase
 
     assert_equal exception.message, "Unknown key: :passing. Valid keys are: :words_connector, :two_words_connector, :last_word_connector, :locale"
   end
+
+  def test_always_returns_string
+    assert_instance_of String, [ActiveSupport::SafeBuffer.new('one')].to_sentence
+    assert_instance_of String, [ActiveSupport::SafeBuffer.new('one'), 'two'].to_sentence
+    assert_instance_of String, [ActiveSupport::SafeBuffer.new('one'), 'two', 'three'].to_sentence
+  end
 end
 
 class ToSTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/array/grouping_test.rb b/activesupport/test/core_ext/array/grouping_test.rb
index b8cfe9728c..2eb0f05141 100644
--- a/activesupport/test/core_ext/array/grouping_test.rb
+++ b/activesupport/test/core_ext/array/grouping_test.rb
@@ -90,6 +90,12 @@ class GroupingTest < ActiveSupport::TestCase
     assert_equal [[1, 2, 3], [4, 5], [6, 7]],
       (1..7).to_a.in_groups(3, false)
   end
+
+  def test_in_groups_invalid_argument
+    assert_raises(ArgumentError) { [].in_groups_of(0) }
+    assert_raises(ArgumentError) { [].in_groups_of(-1) }
+    assert_raises(ArgumentError) { [].in_groups_of(nil) }
+  end
 end
 
 class SplitTest < ActiveSupport::TestCase