tests for unsupported content headers

spec/driver_spec.rb

@@ -140,12 +140,16 @@
       @app = lambda do |env|
         [200, {"Content-Type" => "text/css", "Content-Length" => body.length.to_s}, [body]]
       end
+      subject.visit("/")
     end
 
     it "renders unsupported content types gracefully" do
-      subject.visit("/")
       subject.body.should =~ /css/
     end
+
+    it "sets the response headers with respect to the unsupported request" do
+      subject.response_headers["Content-Type"].should == "text/css"
+    end
   end
 
   context "hello app" do