       res.status.should.equal 200
       callback user, data, get, post
 
+# Verify JSONP Helper - Given a JSONP response, invokes callback with json.
+verifyJSONP = (res, callback) ->
+  res.type.should.equal 'text/javascript'
+  res.text.should.exist
+  jsonp = res.text
+  jsonpCallback = (json) ->
+    callback(json)
+  eval jsonp
+
 # Superagent helpers.
 agent = superagent.agent()
 get = getFor agent

                target_sha1: argument.sha1
              json.argument.should.eql argument
              done()
            eval jsonp

          sha1: prop.sha1
          text: prop.text

    describe 'GET /arguments/:sha1/propositions.:format?', ->
      it "should return argument propositions as json", (done) ->
        sessionWithArgument (user, argument, get, post) ->
