RSPEC - comment out controller action, test still passing? Ruby on Rails

Im pretty new to testing, I am just adding tests to an already existing application, here is my controller:

class JobsController < ApplicationController
  before_action :set_job, only: [:show, :edit, :update, :destroy]

   def index
     if params[:filter]
       @jobs = Job.order(applied_on: :asc)
     else
       @jobs = Job.all
     end
   end
end

Here is my spec file:

```

require 'rails_helper'

RSpec.describe JobsController, type: :controller do describe "#index" do

 it "should render index template" do 
   get(:index)
   expect(response).to render_template(:index)
end

end end

```

If i comment out the entire index action, and run the test - it still passes ? Why is this ?

Other scenerios I tried: Commenting out the routes resources :jobs makes the test fail

How can i fix this issue - cause its clear that the test is passing regardless of it testing the proper thing that needs to be tested here