argument_value should be nil if the option expects an argument and none is given, added tests

2 files changed, 8 insertions, 0 deletions

diff --git a/lib/slop.rb b/lib/slop.rb
index 198483b..40f5d55 100644
--- a/lib/slop.rb
+++ b/lib/slop.rb
@@ -109,6 +109,7 @@ private
             option.argument_value = argument
             option.callback.call(option.argument_value) if option.has_callback?
           else
+            option.argument_value = nil
             if option.accepts_optional_argument?
               option.callback.call(nil) if option.has_callback?
             else
diff --git a/test/option_test.rb b/test/option_test.rb
index ca34b2a..1b7825a 100644
--- a/test/option_test.rb
+++ b/test/option_test.rb
@@ -77,4 +77,11 @@ class OptionTest < TestCase
     assert_equal "        --age       Your age", slop.options[:age].to_s
     assert_equal "    -V,             Display the version", slop.options[:V].to_s
   end
+
+  test 'falls back to default option' do
+    slop = Slop.new
+    slop.opt :foo, :optional => true, :default => 'lee'
+    slop.parse %w/--foo/
+    assert_equal 'lee', slop[:foo]
+  end
 end