zet*_*tic 10

我不确定这是不是您的意思,但您可以设置请求标头以指示JSON:

  describe "POST 'create'" do
    it "should be successful" do
      request.env["HTTP_ACCEPT"] = "application/json"
      post 'create', :article => { :title => "Foo" }.to_json
      response.should be_success
    end
  end
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