1 files changed, 24 insertions, 0 deletions
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index ccc3355930..304bd585a4 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -1740,4 +1740,28 @@ class TestHash < Test::Unit::TestCase
       super
     end
   end
+
+  ruby2_keywords def get_flagged_hash(*args)
+    args.last
+  end
+
+  def check_flagged_hash(k: :NG)
+    k
+  end
+
+  def test_ruby2_keywords_hash?
+    flagged_hash = get_flagged_hash(k: 1)
+    assert_equal(true, Hash.ruby2_keywords_hash?(flagged_hash))
+    assert_equal(false, Hash.ruby2_keywords_hash?({}))
+    assert_raise(TypeError) { Hash.ruby2_keywords_hash?(1) }
+  end
+
+  def test_ruby2_keywords_hash!
+    hash = {k: 1}
+    assert_equal(false, Hash.ruby2_keywords_hash?(hash))
+    hash = Hash.ruby2_keywords_hash(hash)
+    assert_equal(true, Hash.ruby2_keywords_hash?(hash))
+    assert_equal(1, check_flagged_hash(*[hash]))
+    assert_raise(TypeError) { Hash.ruby2_keywords_hash(1) }
+  end
 end