favorites: convert user.hide_favorites? to pundit.

app/logical/post_query_builder.rb

@@ -852,31 +852,30 @@ class PostQueryBuilder
             when "-fav"
               favuser = User.find_by_name(g2)
 
-              if favuser.hide_favorites?
-                raise User::PrivilegeError.new
+              if favuser.nil? || !Pundit.policy!([CurrentUser.user, nil], favuser).can_see_favorites?
+                raise User::PrivilegeError
               end
 
-              q[:tags][:exclude] << "fav:#{User.name_to_id(g2)}"
+              q[:tags][:exclude] << "fav:#{favuser.id}"
 
             when "fav"
               favuser = User.find_by_name(g2)
 
-              if favuser.hide_favorites?
-                raise User::PrivilegeError.new
+              if favuser.nil? || !Pundit.policy!([CurrentUser.user, nil], favuser).can_see_favorites?
+                raise User::PrivilegeError
               end
 
-              q[:tags][:related] << "fav:#{User.name_to_id(g2)}"
+              q[:tags][:related] << "fav:#{favuser.id}"
 
             when "ordfav"
-              user_id = User.name_to_id(g2)
-              favuser = User.find(user_id)
+              favuser = User.find_by_name(g2)
 
-              if favuser.hide_favorites?
+              if favuser.nil? || !Pundit.policy!([CurrentUser.user, nil], favuser).can_see_favorites?
                 raise User::PrivilegeError.new
               end
 
-              q[:tags][:related] << "fav:#{user_id}"
-              q[:ordfav] = user_id
+              q[:tags][:related] << "fav:#{favuser.id}"
+              q[:ordfav] = favuser.id
 
             when "search"
               q[:saved_searches] ||= []

app/logical/recommender_service.rb

@@ -54,7 +54,7 @@ module RecommenderService
     end
 
     if user.present?
-      raise User::PrivilegeError if user.hide_favorites?
+      raise User::PrivilegeError unless Pundit.policy!([CurrentUser.user, nil], user).can_see_favorites?
       max_recommendations = params.fetch(:max_recommendations, user.favorite_count + 500).to_i.clamp(0, 50000)
       recs = RecommenderService.recommend_for_user(user, tags: params[:post_tags_match], limit: max_recommendations)
     elsif post.present?

app/models/post.rb

@@ -956,7 +956,9 @@ class Post < ApplicationRecord
     # users who favorited this post, ordered by users who favorited it first
     def favorited_users
       favorited_user_ids = fav_string.scan(/\d+/).map(&:to_i)
-      visible_users = User.find(favorited_user_ids).reject(&:hide_favorites?)
+      visible_users = User.find(favorited_user_ids).select do |user|
+        Pundit.policy!([CurrentUser.user, nil], user).can_see_favorites?
+      end
       ordered_users = visible_users.index_by(&:id).slice(*favorited_user_ids).values
       ordered_users
     end

app/models/user.rb

@@ -673,10 +673,6 @@ class User < ApplicationRecord
   include CountMethods
   extend SearchMethods
 
-  def hide_favorites?
-    !CurrentUser.is_admin? && enable_private_favorites? && CurrentUser.user.id != id
-  end
-
   def initialize_attributes
     self.enable_post_navigation = true
     self.new_post_navigation_layout = true

app/policies/user_policy.rb

@@ -23,6 +23,10 @@ class UserPolicy < ApplicationPolicy
     user.is_member?
   end
 
+  def can_see_favorites?
+    user.is_admin? || record.id == user.id || !record.enable_private_favorites?
+  end
+
   def permitted_attributes_for_create
     [:name, :password, :password_confirmation, { email_address_attributes: [:address] }]
   end

app/views/users/_post_summary.html.erb

@@ -11,7 +11,7 @@
   </div>
 <% end %>
 
-<% if presenter.has_favorites? && !user.hide_favorites? %>
+<% if presenter.has_favorites? && policy(user).can_see_favorites? %>
   <div class="box user-favorites">
     <h2>
       <%= link_to "Favorites", posts_path(tags: "ordfav:#{user.name}") %>

test/functional/recommended_posts_controller_test.rb

@@ -36,6 +36,12 @@ class RecommendedPostsControllerTest < ActionDispatch::IntegrationTest
         assert_select ".recommended-posts"
         assert_select ".recommended-posts #post_#{@post.id}"
       end
+
+      should "not show recommendations for users with private favorites to other users" do
+        @other_user = create(:user, enable_private_favorites: true)
+        get_auth recommended_posts_path(search: { user_id: @other_user.id }), @user
+        assert_response 403
+      end
     end
   end
 end