Ruby return & ensure gotcha

If you have return and ensure in your method, be very very careful. What happens is when you call return, the method will not return immediately, but it will execute the ensure block.

This can become a problem on Rails and I guess most of other things.

  def some_action
    return render :action => 'something' if some_condition
    # do other things
  rescue Exception => ex
    # handle exception
  ensure
    if other_condition
      render :action => 'other_thing'
    else
      render :action => 'default'
    end
  end

Let's say some_condition is true, you'll end up with the render inside ensure block and things will get double rendering fun.