How to write feature spec when submitting form with remote: true

I am very new to RSpec just starting to test few things.

I have a form with "remote: true" and want to write a spec case for that.

  .row
   .col-md-offset-4.col-md-4.col-sm-offset-3.col-sm-6
    = form_for @reading, html: {class: 'form-inline'}, remote: true do |f|
    #error_box
    .row
     .col-md-9
      .input-group.full-width
       = f.text_field :label, class: 'form-control', placeholder: t('readings.new.lable_placeholder')
       %span.input-group-addon mg/dl
    .col-md-3
     = f.submit t('readings.new.enter'), class: 'btn btn-success full-width' 
   #reading_panel
    = render partial: 'reading_panel', locals: {readings: @readings}

Here is my controller

 def create
   @reading = current_user.readings.create(reading_params)
 end

create.js.erb that re-renders partials.

   <% if @reading.valid? %>
     $("#reading_panel").html("<%= j render partial: 'reading_panel',   locals: {readings: @readings} %>");
     $("#reading_label").val('');
   <% else %>
     $("#error_box").html("<%= j render partial: 'shared/error_messages', locals: {reading: @reading} %>");
   <% end %>

spec with following code

     scenario "add a new reading" do
       visit  new_reading_url

       within "#new_reading" do
        fill_in "reading_label" , with:10
        submit_button = page.find("input[type=submit][value='Enter']")
        submit_button.click
        expect(Reading.count).to eq(1) 
       end
    end

So what i want to ask is how can i test that response is a js response and check if the partials are rendered or not inside the create.js.erb .

Any help will be much appreciated!!

Solution

You shouldn't be checking types of responses in feature tests, just check that the changes you expect to happen on screen happen (you also really shouldn't be directly checking counts in the database in most cases). If you have setup capybara, rspec, and database_cleaner in the normally recommended manor (and selected a javascript capable driver - defaults to selenium) then your test would be something like

scenario "add a new reading", js: true do # in recommended config js: true tells the test to use Capybara.javascript_driver
  visit  new_reading_url

  within "#new_reading" do
   fill_in "reading_label" , with: '10'
   click_button('Enter')
  end

  expect(page).to have_css('#reading_panel', text: '10') # assuming it just renders the submitted text into the panel
  expect(page).to have_field('reading_label', with: '') # verify the input was cleared
end