create js file for fav button

app/controllers/favorites_controller.rb

 class FavoritesController < ApplicationController
   before_action :authenticate_user!, only: [:create, :destroy]
+  before_action :find_favorited_job, only: [:create, :destroy]
 
   def create
     redirect_to new_user_session_path unless user_signed_in?
-    redirect_to jobs_path if params[:job_id].blank?
+    redirect_to jobs_path if @job.id.blank?
 
-    @job_id = params[:job_id]
-    @all_favorite_job.find_by(job_id: @job_id) ||
-    @all_favorite_job.create!(user_id: current_user.id, job_id: @job_id, favorited_at: Time.current)
+    job_id = @job.id
+    @all_favorite_job.find_by(job_id: job_id) ||
+    @all_favorite_job.create!(user_id: current_user.id, job_id: job_id, favorited_at: Time.current)
+
+    redirect_to job_path(job_id)
   end
 
   def destroy
     redirect_to new_user_session_path unless user_signed_in?
-    redirect_to jobs_path if params[:job_id].blank?
+    redirect_to jobs_path if @job.id.blank?
+
+    job_id = @job.id
+    @all_favorite_job.find_by(job_id: job_id).destroy
 
-    @job_id = params[:job_id]
-    @all_favorite_job.find_by(job_id: @job_id).destroy
+    redirect_to job_path(job_id)
   end
 
   private

app/views/favorites/create.js.erb

+$("#favorite_form_<%= @job.id %>").html("<%= escape_javascript(render "shared/unfavorite_btn", job: @job %>");

app/views/favorites/destroy.js.erb

+$("#favorite_form_<%= @job.id %>").html("<%= escape_javascript(render "shared/favorite_btn", job: @job) %>");

app/views/jobs/_job.html.erb

@@ -17,5 +17,12 @@
       <dd><%= job["city"] %></dd>
     </dl>
   </div>
-  <button type="button" class="btn btn-outline-secondary">Favorite</button>
+  <div id="favorite_form_">
+    <button type="button" class="btn btn-outline-secondary">Favorite</button>
+    <% if current_user.favorites.exists?(job_id: job.id) %>
+      <%= render "shared/unfavorite_btn", job_id: job.id %>
+    <% else %>
+      <%= render "shared/favorite_btn", job_id: job.id %>
+    <% end %>
+  </div>
 </div>

app/views/shared/_favorite_btn.html.erb

 <% if user_signed_in? %>
-  <%= link_to "Favorite", "#", class: "btn btn-primary float-right" %>
+  <%= form_tag(jobs_favorites_path(job_id: @job.id) , remote: true) do %>
+    <%= submit_tag "Favorite", class: "btn btn-primary float-right" %>
+  <% end %>
 <% else %>
   <button type="button" class="btn btn-primary float-right" disabled>Favorite</button>
 <% end %>

app/views/shared/_unfavorite_btn.html.erb

 <% if user_signed_in? %>
-  <%= link_to "Unfavorite", "#", class: "btn btn-primary float-right" %>
+  <%= form_tag(jobs_favorite_path(job_id: @job.id), method: :delete, remote: true) do  %>
+    <%= submit_tag "Unfavorite", class: "btn btn-primary float-right" %>
+  <% end %>
 <% else %>
   <button type="button" class="btn btn-primary float-right" disabled>Unfavorite</button>
 <% end %>

config/routes.rb

@@ -24,4 +24,8 @@ Rails.application.routes.draw do
   resource :favorites, only: [:create, :destroy]
   # post "favorite", to: "favorites#create"
   # delete "unfavorite", to: "favorites#destroy"
+
+  resource :jobs do
+    resource :favorites, only: [:create, :destroy]
+  end
 end