Accept FileList object as directory task's target

Author: gemmaro

lib/rake/dsl_definition.rb

@@ -90,6 +90,7 @@ def file_create(*args, &block)
     #   directory "testdata/doc"
     #
     def directory(*args, &block) # :doc:
+      args = args.flat_map { |arg| arg.is_a?(FileList) ? arg.to_a.flatten : arg }
       result = file_create(*args, &block)
       dir, _ = *Rake.application.resolve_args(args)
       dir = Rake.from_pathname(dir)

test/test_rake_directory_task.rb

@@ -74,4 +74,16 @@ def test_can_use_pathname
 
     assert File.directory?("a/b/c")
   end
+
+  def test_can_use_filelist
+    directory FileList["a", "b", "c"]
+
+    assert_equal FileCreationTask, Task["a"].class
+
+    verbose(false) {
+      Task["a"].invoke
+    }
+
+    assert File.directory?("a")
+  end
 end