很多挫折和变化，这对我有用.Rails 3.2.12 Rspec 2.10

A lot of frustration and variations and that's what worked for me. Rails 3.2.12 Rspec 2.10

 @request.env["HTTP_ACCEPT"] = "application/json"
 @request.env["CONTENT_TYPE"] = "application/json"
 put :update, :id => 1, "email" => "bing@test.com"

wrap_parameters 似乎以这种方式声明

wrap_parameters seems to be working declared this way

wrap_parameters User, format: :json

用于User模型