class Spec::Rails::Example::ControllerExampleGroup

def integrate_views(integrate_views = true)

Integration and Isolation modes.
See Spec::Rails::Example::ControllerExampleGroup for more information about

...
integrate_views
describe ThingController do

Use this to instruct RSpec to render views in your controller examples (Integration Mode). 
def integrate_views(integrate_views = true)
  @integrate_views = integrate_views
end