AI: address review on PR #468

backend/app/controllers/posts_controller.rb

@@ -314,7 +314,9 @@ class PostsController < ApplicationController
   def viewed
     return head :unauthorized unless current_user
 
-    current_user.viewed_posts << Post.find(params[:id])
+    UserPostView.create_or_find_by!(
+        user: current_user,
+        post: Post.find(params[:id]))
     head :no_content
   end
 

backend/app/controllers/tag_versions_controller.rb

@@ -69,11 +69,8 @@ class TagVersionsController < ApplicationController
 
       parent_tags =
           build_version_values(cur_parent_tag_ids, prev_parent_tag_ids, key: :tag_id)
-          .filter_map do |h|
-            parent = parent_json[h[:tag_id]]
-            next unless parent
-
-            { tag: parent,
+          .map do |h|
+            { tag: parent_json.fetch(h[:tag_id]),
               type: h[:type] }
           end
 

backend/spec/requests/posts_spec.rb

@@ -2559,6 +2559,21 @@ RSpec.describe 'Posts API', type: :request do
 
       expect(user.reload.viewed?(post_record)).to be(true)
     end
+
+    it '204 and keeps one view on repeated requests' do
+      sign_in_as(user)
+
+      expect {
+        post "/posts/#{ post_record.id }/viewed"
+      }.to change(UserPostView, :count).by(1)
+      expect(response).to have_http_status(:no_content)
+
+      expect {
+        post "/posts/#{ post_record.id }/viewed"
+      }.not_to change(UserPostView, :count)
+      expect(response).to have_http_status(:no_content)
+      expect(user.reload.viewed?(post_record)).to be(true)
+    end
   end
 
   describe 'DELETE /posts/:id/viewed' do

backend/spec/requests/tag_versions_spec.rb

@@ -215,36 +215,6 @@ RSpec.describe 'TagVersions API', type: :request do
       expect(first.fetch('created_at')).to eq(t_v1.iso8601)
     end
 
-    [:parent_shared, :parent_new, :parent_old].each do |parent_key|
-      it "omits deleted #{ parent_key } from parent diffs" do
-        deleted_parent = public_send(parent_key)
-        deleted_parent.tag_names.destroy_all
-        deleted_parent.destroy!
-
-        get '/tags/versions', params: { id: tag.id }
-
-        expect(response).to have_http_status(:ok)
-        expect(json.fetch('count')).to eq(2)
-
-        versions = json.fetch('versions')
-        expect(versions.map { _1.fetch('version_no') }).to eq([2, 1])
-
-        expected_parents = [
-            [parent_shared.id, 'context'],
-            [parent_new.id, 'added'],
-            [parent_old.id, 'removed']].reject { _1.first == deleted_parent.id }
-        expect(versions.first.fetch('parent_tags').map { |entry|
-          [entry.fetch('tag').fetch('id'), entry.fetch('type')]
-        }).to eq(expected_parents)
-
-        expected_first_parents = [parent_shared.id, parent_old.id]
-            .reject { _1 == deleted_parent.id }.map { [_1, 'added'] }
-        expect(versions.second.fetch('parent_tags').map { |entry|
-          [entry.fetch('tag').fetch('id'), entry.fetch('type')]
-        }).to eq(expected_first_parents)
-      end
-    end
-
     it 'returns empty when the specified tag has no versions' do
       fresh_tag = create(:tag, primary_name: 'no_versions_tag', category: :general)