Added nested array test

spec/signature_spec.rb

@@ -75,6 +75,15 @@
         "POST\n/some/path\nthings[][thing_1]=value1&things[][thing_2]=value2"
     end
 
+    it "should generate correct string when query hash contains nested arrays" do
+      @request.query_hash = {
+        "things" => [{ "thing_1" => [["v1", "v1"]] }, { "thing_2" => [["v2", "v2"]] }]
+      }
+      @request.send(:string_to_sign).should ==
+        "POST\n/some/path\nthings[][thing_1][][]=v1&things[][thing_1][][]=v1"\
+        "&things[][thing_2][][]=v2&things[][thing_2][][]=v2"
+    end
+
     # This may well change in auth version 2
     it "should not escape keys or values in the query string" do
       @request.query_hash = {