missing a template for this request format and variant for shopping cart app

i am creating a simple shopping cart but when i click add to cart i am getting a message error saying OrderItemsController#create is missing a template for this request format and variant. request.formats: ["text/html"] request.variant: [] i have orderitem route setup and the create.js.erb file setup i dont understand why i am getting this error any solution here my code.

---

errror message

 "\nrequest.variant: #{request.variant.inspect}"

        raise ActionController::UnknownFormat, message
      elsif interactive_browser_request?
        message = "#{self.class.name}\##{action_name} is missing a template " \
          "for this request format and variant.\n\n" \

---

orderItem.controller.rb

class OrderItemsController < ApplicationController
    def create
        @order = current_order
        @order_item = @order.order_items.new(order_item_params)
        @order.save
        session[:order_id] = @order.id
    end

    def update
        @order = current_order
        @order_item = @order.order_items.find(params[:id])
        @order_item.update_attributes(order_item_params)
        @order_items = @order.order_items
    end

    def destroy
        @order = current_order
        @order_item = @order.order_items.find(params[:id])
        @order_item.destroy
        @order_items = @order.order_items
    end

    private
        def order_item_params
            params.require(:order_item).permit(:product_id, :quantity)
        end
end

---

create.js.erb

<% if @order.errors.any? || @order_item.errors.any? %>
    alert("Invalid")
<% else %>
    $(".cart").html("<%= escape_javascript(render 'layouts/cart') %>")
<% end %>

---

route

Rails.application.routes.draw do
  resources :products
  resources :order_items
  resource :carts, only: [:show]

  root 'welcomes#index'

  devise_for :users
  # For details on the DSL available within this file, see http://ift.tt/GVpneB
end

---

_cart.html.erb

<%= link_to "#{current_order.order_items.size} items in card and price #{current_order.subtotal}", carts_path %>