FIX: sort by topic activity when searching in:title (#36630)

ZogStriP · web-flow · commit 3997ce5e1c0b · 2025-12-11T14:28:59.000+01:00
When using `in:title` (or `t`), search results were sorted by the first
post's creation date instead of the topic's last activity. This caused
topics with recent replies to appear lower than older topics with no
activity, which was unintuitive.

For example, a topic created 5 years ago with a reply yesterday would
appear below a topic created last week with no replies, even though the
user expects "Latest Post" to show recently active topics first.

Now when `@in_title` is true, we sort by `topics.bumped_at` instead of
`posts.created_at`, matching user expectations for topic-level searches.

Internal ref - t/170642
diff --git a/lib/search.rb b/lib/search.rb
@@ -844,13 +844,17 @@ def apply_order(
     type_filter: "all_topics"
   )
     if @order == :latest
-      if aggregate_search
+      if @in_title
+        posts = posts.order("topics.bumped_at DESC")
+      elsif aggregate_search
         posts = posts.order("MAX(posts.created_at) DESC")
       else
         posts = posts.reorder("posts.created_at DESC")
       end
     elsif @order == :oldest
-      if aggregate_search
+      if @in_title
+        posts = posts.order("topics.bumped_at ASC")
+      elsif aggregate_search
         posts = posts.order("MAX(posts.created_at) ASC")
       else
         posts = posts.reorder("posts.created_at ASC")
diff --git a/spec/lib/search_spec.rb b/spec/lib/search_spec.rb
@@ -2841,6 +2841,33 @@ def indexed_post(*args)
       results = Search.execute("in:title status:open Discourse")
       expect(results.posts.length).to eq(1)
     end
+
+    it "sorts by topic bumped_at" do
+      old_bumped_topic =
+        Fabricate(:topic, title: "Old bumped topic about Discourse", bumped_at: 1.day.ago)
+      new_bumped_topic =
+        Fabricate(:topic, title: "New bumped topic about Discourse", bumped_at: 1.hour.ago)
+
+      Fabricate(
+        :post,
+        topic: old_bumped_topic,
+        raw: "This is the first post",
+        created_at: 1.hour.ago,
+      )
+
+      Fabricate(
+        :post,
+        topic: new_bumped_topic,
+        raw: "This is the first post",
+        created_at: 1.day.ago,
+      )
+
+      results = Search.execute("Discourse in:title order:latest")
+      expect(results.posts.map(&:topic_id)).to eq([new_bumped_topic.id, old_bumped_topic.id])
+
+      results = Search.execute("Discourse in:title order:oldest")
+      expect(results.posts.map(&:topic_id)).to eq([old_bumped_topic.id, new_bumped_topic.id])
+    end
   end
 
   describe "include:invisible / include:unlisted" do
