FEATURE: Order pinned topics by their `pinned_at` column (#14090)

Currently, pinned topics are ordered by the `bumped_at` column. This behavior is not desired because it gives admins no control over the order of pinned topics. This PR makes pinned topics ordered by the `pinned_at` column. A topic that is pinned last appears first in topic lists. If an admin wants an already pinned topic to appear first in the list of pinned topics, they'll have to unpin that topic and pin it again.

Meta topic: https://meta.discourse.org/t/how-do-i-set-the-order-of-pinned-topics/16935/23?u=osama.

lib/topic_query.rb

@@ -390,7 +390,7 @@ class TopicQuery
     end
 
     unpinned_topics = topics.where("NOT ( #{pinned_clause} )")
-    pinned_topics = topics.dup.offset(nil).where(pinned_clause)
+    pinned_topics = topics.dup.offset(nil).where(pinned_clause).reorder(pinned_at: :desc)
 
     per_page = options[:per_page] || per_page_setting
     limit = per_page unless options[:limit] == false

spec/components/topic_query_spec.rb

@@ -97,6 +97,63 @@ describe TopicQuery do
         page: 1)
       ).to eq(topics[per_page...num_topics])
     end
+
+    it "orders globally pinned topics by pinned_at rather than bumped_at" do
+      pinned1 = Fabricate(
+        :topic,
+        bumped_at: 3.hour.ago,
+        pinned_at: 1.hours.ago,
+        pinned_until: 10.days.from_now,
+        pinned_globally: true
+      )
+      pinned2 = Fabricate(
+        :topic,
+        bumped_at: 2.hour.ago,
+        pinned_at: 4.hours.ago,
+        pinned_until: 10.days.from_now,
+        pinned_globally: true
+      )
+      unpinned1 = Fabricate(:topic, bumped_at: 2.hour.ago)
+      unpinned2 = Fabricate(:topic, bumped_at: 3.hour.ago)
+
+      topic_query = TopicQuery.new(user)
+      results = topic_query.send(:default_results)
+
+      expected_order = [pinned1, pinned2, unpinned1, unpinned2].map(&:id)
+      expect(topic_query
+        .prioritize_pinned_topics(results, per_page: 10, page: 0)
+        .pluck(:id)
+      ).to eq(expected_order)
+    end
+
+    it "orders pinned topics within a category by pinned_at rather than bumped_at" do
+      cat = Fabricate(:category)
+      pinned1 = Fabricate(
+        :topic,
+        category: cat,
+        bumped_at: 3.hour.ago,
+        pinned_at: 1.hours.ago,
+        pinned_until: 10.days.from_now,
+      )
+      pinned2 = Fabricate(
+        :topic,
+        category: cat,
+        bumped_at: 2.hour.ago,
+        pinned_at: 4.hours.ago,
+        pinned_until: 10.days.from_now,
+      )
+      unpinned1 = Fabricate(:topic, category: cat, bumped_at: 2.hour.ago)
+      unpinned2 = Fabricate(:topic, category: cat, bumped_at: 3.hour.ago)
+
+      topic_query = TopicQuery.new(user)
+      results = topic_query.send(:default_results)
+
+      expected_order = [pinned1, pinned2, unpinned1, unpinned2].map(&:id)
+      expect(topic_query
+        .prioritize_pinned_topics(results, per_page: 10, page: 0, category_id: cat.id)
+        .pluck(:id)
+      ).to eq(expected_order)
+    end
   end
 
   context 'bookmarks' do