test_rdoc_options.diff

diff --git a/test/test_rdoc_options.rb b/test/test_rdoc_options.rb
index 5d7135c..97fd4ef 100644
--- a/test/test_rdoc_options.rb
+++ b/test/test_rdoc_options.rb
@@ -220,6 +220,18 @@ rdoc_include:
     assert_equal 1, @options.coverage_report
   end
 
+  def test_parse_needless_arg
+    assert_raises OptionParser::NeedlessArgument do
+      @options.parse %w[--ri=foo]
+    end
+  end
+
+  def test_parse_missing_arg
+    assert_raises OptionParser::MissingArgument do
+      @options.parse %w[--copy-files]
+    end
+  end
+
   def test_parse_dash_p
     out, err = capture_io do
       @options.parse %w[-p]