1 files changed, 9 insertions, 0 deletions
diff --git a/test/rdoc/test_rdoc_options.rb b/test/rdoc/test_rdoc_options.rb
index 763f50b5f0..2f74f45b45 100644
--- a/test/rdoc/test_rdoc_options.rb
+++ b/test/rdoc/test_rdoc_options.rb
@@ -337,6 +337,15 @@ file 'unreadable' not readable
     $LOAD_PATH.replace orig_LOAD_PATH
   end
 
+  def test_parse_extension_alias
+    out, err = capture_io do
+      @options.parse %w[--extension foobar=rdoc]
+    end
+
+    assert_empty out
+    assert_empty err
+  end
+
   def test_setup_generator
     test_generator = Class.new do
       def self.setup_options op