#163 only raise MissingArgument if not default_value

2 files changed, 11 insertions, 3 deletions

diff --git a/lib/slop/option.rb b/lib/slop/option.rb
index 2164f1d..3e414f9 100644
--- a/lib/slop/option.rb
+++ b/lib/slop/option.rb
@@ -47,11 +47,16 @@ module Slop
     def ensure_call(value)
       @count += 1
 
-      if value.nil? && expects_argument? && !suppress_errors?
-        raise Slop::MissingArgument.new("missing argument for #{flag}", flags)
+      if value.nil? && expects_argument?
+        if default_value
+          @value = default_value
+        elsif !suppress_errors?
+          raise Slop::MissingArgument.new("missing argument for #{flag}", flags)
+        end
+      else
+        @value = call(value)
       end
 
-      @value = call(value)
       block.call(@value) if block.respond_to?(:call)
     end
 
diff --git a/test/result_test.rb b/test/result_test.rb
index 0efdfff..3fa61f6 100644
--- a/test/result_test.rb
+++ b/test/result_test.rb
@@ -32,6 +32,9 @@ describe Slop::Result do
     @options.string("--foo", default: "bar")
     @result.parser.parse %w()
     assert_equal "bar", @result[:foo]
+
+    @result.parser.parse %w(--foo)
+    assert_equal "bar", @result[:foo]
   end
 
   it "handles custom finishing" do