【Rails】いいね機能の非同期通信化がページをリロードしないと表示されない

Question

前提・実現したいこと

Rails初心者です。
Ruby on railsで、各ユーザーが投稿（Book）できるアプリを開発しています。
投稿一覧画面と投稿詳細画面に、非同期通信のいいね機能を実装しようとしていますが、ページをリロードしないと表示されません。
※備考
いいねは以下のように切り替わります。
いいね（０）　　＜＝＞　　いいねを消す（１）

発生している問題・エラーメッセージ

Logには以下のようなメッセージが表示されました。
「undefined method `favorited_by?' 」とありますが、book.rbに定義しているので
原因がわかりません。

Started DELETE "/books/1/favorites" for 211.120.130.120 at 2021-12-24 06:11:36 +0000
Cannot render console from 211.120.130.120! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by FavoritesController#destroy as JS
  Parameters: {"book_id"=>"1"}
  User Load (0.1ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT ?  [["id", 1], ["LIMIT", 1]]
  ↳ /home/ec2-user/.rvm/gems/ruby-2.6.3/gems/activerecord-5.2.5/lib/active_record/log_subscriber.rb:98
  Book Load (0.1ms)  SELECT  "books".* FROM "books" WHERE "books"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
  ↳ app/controllers/favorites_controller.rb:9
  Favorite Load (0.2ms)  SELECT  "favorites".* FROM "favorites" WHERE "favorites"."user_id" = ? AND "favorites"."book_id" = ? LIMIT ?  [["user_id", 1], ["book_id", 1], ["LIMIT", 1]]
  ↳ app/controllers/favorites_controller.rb:10
   (0.1ms)  begin transaction
  ↳ app/controllers/favorites_controller.rb:11
  Favorite Destroy (0.2ms)  DELETE FROM "favorites" WHERE "favorites"."id" = ?  [["id", 33]]
  ↳ app/controllers/favorites_controller.rb:11
   (6.5ms)  commit transaction
  ↳ app/controllers/favorites_controller.rb:11
  Rendering favorites/destroy.js.erb
  Rendered favorites/_favorite.html.erb (3.2ms)
  Rendered favorites/destroy.js.erb (5.8ms)
Completed 500 Internal Server Error in 27ms (ActiveRecord: 7.2ms)


  
ActionView::Template::Error (undefined method `favorited_by?' for nil:NilClass):
    1: <% if book.favorited_by?(current_user) %>
    2:     <td><%= link_to book_favorites_path(book.id), method: :delete, remote: true do %>
    3:     ♥<%= book.favorites.count %> いいね</td>
    4:   <% end %>
  
app/views/favorites/_favorite.html.erb:1:in `_app_views_favorites__favorite_html_erb___640992299850121874_69917787488560'
app/views/favorites/destroy.js.erb:1:in `_app_views_favorites_destroy_js_erb___1919995251382630832_69917787431440'

該当のソースコード

views/favorites/create.js.erb
views/favorites/delete.js.erb

$("#favorites_buttons_<%= @books %>").html("<%= j(render partial:  'favorites/favorite', locals:{book: @books})%>");

favorites_controller.rb

def create
    book = Book.find(params[:book_id])
    favorite = current_user.favorites.new(book_id: book.id)
    favorite.save
  end

  def destroy
    book = Book.find(params[:book_id])
    favorite = current_user.favorites.find_by(book_id: book.id)
    favorite.destroy
  end
end

views/favorites/_favorite.html.erb

<% if book.favorited_by?(current_user) %>
    <td><%= link_to book_favorites_path(book.id), method: :delete, remote: true do %>
    ♥<%= book.favorites.count %> いいね</td>
  <% end %>
  <% else %>
    <td><%= link_to book_favorites_path(book.id), method: :post, remote: true do %>
    ♡<%= book.favorites.count %> いいね</td>
  <% end %>
<% end %>

views/books/show.html.erb

<div id="favorite_btn_<%= @books.id %>">
 <%= render partial: 'favorites/favorite', locals: { book: @books} %>
  </div>

views/books/_index.html.erb

 <div id="favorite_btn_<%= book.id %>">
  <%= render partial: 'favorites/favorite', locals: { book: book} %>
  </div>

books_controller.erb

 def show
    @books = Book.find(params[:id])
    @user = @books.user
    @book = Book.new
    @book_comment = BookComment.new
  end

  def index
    @book = Book.new
    @books = Book.all
    @user = current_user
  end

models/book.rb

class Book < ApplicationRecord
	belongs_to :user
	has_many :favorites, dependent: :destroy
	has_many :book_comments, dependent: :destroy
	
	def favorited_by?(user)
    favorites.where(user_id: user.id).exists?
	end

	validates :title, presence: true
	validates :body, presence: true, length: {maximum: 200}
end

routes

Rails.application.routes.draw do
  get 'search/search'
  devise_for :users
  root 'homes#top'
  get 'home/about' => 'homes#about'
  get "users/show" => "users#show"
  get '/users' => "users#index"
  get "users/:id" => "users#show", as: :mypage
  get 'search' => "search#search"
  resources :users,only: [:show,:index,:edit,:update] do
    resources :relationships, only: [:create, :destroy]
    get :followings, on: :member
    get :followers, on: :member
  end
  resources :books do
    resource :favorites, only: [:create, :destroy]
    resources :book_comments, only: [:create, :destroy]
  end 
end

application.js

// This is a manifest file that'll be compiled into application.js, which will include all the files
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, or any plugin's
// vendor/assets/javascripts directory can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// compiled file. JavaScript code in this file should be added after the last require_* statement.
//
// Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
// about supported directives.
//
//= require jquery3
//= require popper
//= require bootstrap-sprockets
//= require jquery
//= require rails-ujs
//= require activestorage
//= require turbolinks
//= require_tree .

試したこと

ここに問題に対して試したことを記載してください。

補足情報（FW/ツールのバージョンなど）

ここにより詳細な情報を記載してください。

どうぞ宜しくお願い致します。