Rspec: How to test create action in controller

Renders and redirects in Rails do not trigger a halt on the http stack
so you need to trigger the halt yourself inside of the action by using
"return render :blah" in your if or "return redirect_to :back". What
I am saying is if you have a conditional and you render and then have
another render it will trigger a double render because it does not
halt the http and render or redirect, it continues to let you finish
your job if you need to... such as closing off connections and
what-have-you. An example:

MyController < ApplicationController
  def my_action
     redirect_to :back unless params["blah"] == "blah"
     render :my_template
  end
end

Should be:

MyController < ApplicationController
  def my_action
     return redirect_to :back unless params["blah"] == "blah"
     render :my_template
  end
end

To add before somebody points it out, I would never personally write a
simple method like that, I would instead prefer to do something like:

MyController < ApplicationController
  def my_action
    prams["blah"] == "blah" ? render(:my_template) : redirect_to(:back)
  end
end