1 files changed, 19 insertions, 0 deletions
diff --git a/test/ostruct/test_ostruct.rb b/test/ostruct/test_ostruct.rb
index 256db7a0c7..19bb606145 100644
--- a/test/ostruct/test_ostruct.rb
+++ b/test/ostruct/test_ostruct.rb
@@ -412,4 +412,23 @@ class TC_OpenStruct < Test::Unit::TestCase
     assert_equal('my-class', os.class)
     assert_equal(OpenStruct, os.class!)
   end
+
+  has_performance_warnings = begin
+    Warning[:performance]
+    true
+  rescue NoMethodError, ArgumentError
+    false
+  end
+
+  if has_performance_warnings
+    def test_performance_warning
+      assert_in_out_err(
+        %w(-Ilib -rostruct -w -W:performance -e) + ['OpenStruct.new(a: 1)'],
+        "",
+        [],
+        ["-e:1: warning: OpenStruct use is discouraged for performance reasons"],
+        success: true,
+      )
+    end
+  end
 end