FIX: Send quote notifications to correct users when prioritizing full names (#17030)

app/services/post_alerter.rb

@@ -583,8 +583,11 @@ class PostAlerter
   # TODO: Move to post-analyzer?
   # Returns a list of users who were quoted in the post
   def extract_quoted_users(post)
-    usernames = post.raw.scan(/\[quote=\"([^,]+),.+\"\]/).uniq.map { |q| q.first.strip.downcase }
-
+    usernames = if SiteSetting.display_name_on_posts && !SiteSetting.prioritize_username_in_ux
+      post.raw.scan(/username:([[:alnum:]]*)"(?=\])/)
+    else
+      post.raw.scan(/\[quote=\"([^,]+),.+\"\]/)
+    end.uniq.map { |q| q.first.strip.downcase }
     User.where.not(id: post.user_id).where(username_lower: usernames)
   end
 

spec/services/post_alerter_spec.rb

@@ -348,7 +348,7 @@ describe PostAlerter do
     fab!(:topic) { Fabricate(:topic, category: category) }
 
     it 'does not notify for muted users' do
-      post = Fabricate(:post, raw: '[quote="EvilTrout, post:1"]whatup[/quote]', topic: topic)
+      post = Fabricate(:post, raw: '[quote="Eviltrout, post:1"]whatup[/quote]', topic: topic)
       MutedUser.create!(user_id: evil_trout.id, muted_user_id: post.user_id)
 
       expect {
@@ -366,7 +366,7 @@ describe PostAlerter do
     end
 
     it 'does not notify for users with new reply notification' do
-      post = Fabricate(:post, raw: '[quote="EvilTrout, post:1"]whatup[/quote]', topic: topic)
+      post = Fabricate(:post, raw: '[quote="eviltRout, post:1"]whatup[/quote]', topic: topic)
       notification = Notification.create!(topic: post.topic,
                                           post_number: post.post_number,
                                           read: false,
@@ -388,7 +388,7 @@ describe PostAlerter do
       expect {
         2.times do
           create_post_with_alerts(
-            raw: '[quote="EvilTrout, post:1"]whatup[/quote]',
+            raw: '[quote="eviltrout, post:1"]whatup[/quote]',
             topic: topic
           )
         end
@@ -410,12 +410,77 @@ describe PostAlerter do
     end
 
     it "triggers :before_create_notifications_for_users" do
-      post = Fabricate(:post, raw: '[quote="EvilTrout, post:1"]whatup[/quote]')
+      post = Fabricate(:post, raw: '[quote="eviltrout, post:1"]whatup[/quote]')
       events = DiscourseEvent.track_events do
         PostAlerter.post_created(post)
       end
       expect(events).to include(event_name: :before_create_notifications_for_users, params: [[evil_trout], post])
     end
+
+    context "notifications when prioritizing full names" do
+      before do
+        SiteSetting.prioritize_username_in_ux = false
+        SiteSetting.display_name_on_posts = true
+      end
+
+      it 'sends to correct user' do
+        quote = <<~MD
+          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]whatup[/quote]
+        MD
+
+        expect {
+          create_post_with_alerts(
+            raw: quote,
+            topic: topic
+          )
+        }.to change(evil_trout.notifications, :count).by(1)
+      end
+
+      it 'sends to correct users when nested quotes with multiple users' do
+        quote = <<~MD
+          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]this [quote="#{walterwhite.name}, post:2, username:#{walterwhite.username}"]whatup[/quote][/quote]
+        MD
+
+        expect {
+          create_post_with_alerts(
+            raw: quote,
+            topic: topic
+          )
+        }.to change(evil_trout.notifications, :count).by(1)
+          .and change(walterwhite.notifications, :count).by(1)
+      end
+
+      it 'sends to correct users when multiple quotes' do
+        user = Fabricate(:user)
+        quote = <<~MD
+          [quote="#{evil_trout.name}, post:1, username:#{evil_trout.username}"]"username:#{user.username}" [/quote]/n [quote="#{walterwhite.name}, post:2, username:#{walterwhite.username}"]whatup[/quote]
+        MD
+
+        expect {
+          create_post_with_alerts(
+            raw: quote,
+            topic: topic
+          )
+        }.to change(evil_trout.notifications, :count).by(1)
+          .and change(walterwhite.notifications, :count).by(1)
+          .and change(user.notifications, :count).by(0)
+      end
+
+      it "sends to correct user when user has a full name that matches another user's username" do
+        user_with_matching_full_name = Fabricate(:user, name: evil_trout.username)
+        quote = <<~MD
+          [quote="#{user_with_matching_full_name.name}, post:1, username:#{user_with_matching_full_name.username}"]this [/quote]
+        MD
+
+        expect {
+          create_post_with_alerts(
+            raw: quote,
+            topic: topic
+          )
+        }.to change(user_with_matching_full_name.notifications, :count).by(1)
+          .and change(evil_trout.notifications, :count).by(0)
+      end
+    end
   end
 
   context 'linked' do