FIX: Topic.time_to_first_response should include sub-sub-categories (#9349)

app/models/category.rb

@@ -153,6 +153,25 @@ class Category < ActiveRecord::Base
     Category.reset_topic_ids_cache
   end
 
+  def self.subcategory_ids(category_id)
+    sql = <<~SQL
+        WITH RECURSIVE subcategories AS (
+            SELECT :category_id id, 1 depth
+            UNION
+            SELECT categories.id, (subcategories.depth + 1) depth
+            FROM categories
+            JOIN subcategories ON subcategories.id = categories.parent_category_id
+            WHERE subcategories.depth < :max_category_nesting
+        )
+        SELECT id FROM subcategories
+      SQL
+    DB.query_single(
+      sql,
+      category_id: category_id,
+      max_category_nesting: SiteSetting.max_category_nesting
+    )
+  end
+
   def self.scoped_to_permissions(guardian, permission_types)
     if guardian.try(:is_admin?)
       all

app/models/topic.rb

@@ -189,11 +189,6 @@ class Topic < ActiveRecord::Base
     where("topics.category_id IS NULL OR topics.category_id IN (SELECT id FROM categories WHERE #{condition[0]})", condition[1])
   }
 
-  IN_CATEGORY_AND_SUBCATEGORIES_SQL = <<~SQL
-       t.category_id = :category_id
-    OR t.category_id IN (SELECT id FROM categories WHERE categories.parent_category_id = :category_id)
-  SQL
-
   scope :in_category_and_subcategories, lambda { |category_id|
     where("topics.category_id = ? OR topics.category_id IN (SELECT id FROM categories WHERE categories.parent_category_id = ?)",
         category_id,
@@ -1300,7 +1295,7 @@ class Topic < ActiveRecord::Base
     builder = DB.build(sql)
     builder.where("t.created_at >= :start_date", start_date: opts[:start_date]) if opts[:start_date]
     builder.where("t.created_at < :end_date", end_date: opts[:end_date]) if opts[:end_date]
-    builder.where(IN_CATEGORY_AND_SUBCATEGORIES_SQL, category_id: opts[:category_id]) if opts[:category_id]
+    builder.where("t.category_id IN (:subcategory_ids)", subcategory_ids: Category.subcategory_ids(opts[:category_id])) if opts[:category_id]
     builder.where("t.archetype <> '#{Archetype.private_message}'")
     builder.where("t.deleted_at IS NULL")
     builder.where("p.deleted_at IS NULL")
@@ -1339,7 +1334,7 @@ class Topic < ActiveRecord::Base
     builder = DB.build(WITH_NO_RESPONSE_SQL)
     builder.where("t.created_at >= :start_date", start_date: start_date) if start_date
     builder.where("t.created_at < :end_date", end_date: end_date) if end_date
-    builder.where(IN_CATEGORY_AND_SUBCATEGORIES_SQL, category_id: category_id) if category_id
+    builder.where("t.category_id IN (:subcategory_ids)", subcategory_ids: Category.subcategory_ids(category_id)) if category_id
     builder.where("t.archetype <> '#{Archetype.private_message}'")
     builder.where("t.deleted_at IS NULL")
     builder.query_hash
@@ -1359,7 +1354,7 @@ class Topic < ActiveRecord::Base
 
   def self.with_no_response_total(opts = {})
     builder = DB.build(WITH_NO_RESPONSE_TOTAL_SQL)
-    builder.where(IN_CATEGORY_AND_SUBCATEGORIES_SQL, category_id: opts[:category_id]) if opts[:category_id]
+    builder.where("t.category_id IN (:subcategory_ids)", subcategory_ids: Category.subcategory_ids(opts[:category_id])) if opts[:category_id]
     builder.where("t.archetype <> '#{Archetype.private_message}'")
     builder.where("t.deleted_at IS NULL")
     builder.query_single.first.to_i

lib/topic_query.rb

@@ -1054,25 +1054,7 @@ class TopicQuery
 
   def subcategory_ids(category_id)
     @subcategory_ids ||= {}
-    @subcategory_ids[category_id] ||=
+    @subcategory_ids[category_id] ||= Category.subcategory_ids(category_id)
-      begin
-        sql = <<~SQL
-            WITH RECURSIVE subcategories AS (
-                SELECT :category_id id, 1 depth
-                UNION
-                SELECT categories.id, (subcategories.depth + 1) depth
-                FROM categories
-                JOIN subcategories ON subcategories.id = categories.parent_category_id
-                WHERE subcategories.depth < :max_category_nesting
-            )
-            SELECT id FROM subcategories
-          SQL
-        DB.query_single(
-          sql,
-          category_id: category_id,
-          max_category_nesting: SiteSetting.max_category_nesting
-        )
-      end
   end
 
   def sanitize_sql_array(input)

spec/models/topic_spec.rb

@@ -2348,6 +2348,20 @@ describe Topic do
       expect(Topic.time_to_first_response_total).to eq(1)
     end
 
+    it "should have results if there's a topic with replies" do
+      SiteSetting.max_category_nesting = 3
+
+      category = Fabricate(:category_with_definition)
+      subcategory = Fabricate(:category_with_definition, parent_category_id: category.id)
+      subsubcategory = Fabricate(:category_with_definition, parent_category_id: subcategory.id)
+
+      topic = Fabricate(:topic, category: subsubcategory, created_at: 3.hours.ago)
+      Fabricate(:post, topic: topic, user: topic.user, post_number: 1, created_at: 3.hours.ago)
+      Fabricate(:post, topic: topic, post_number: 2, created_at: 2.hours.ago)
+
+      expect(Topic.time_to_first_response_total(category_id: category.id)).to eq(1)
+    end
+
     it "should only count regular posts as the first response" do
       topic = Fabricate(:topic, created_at: 5.hours.ago)
       Fabricate(:post, topic: topic, user: topic.user, post_number: 1, created_at: 5.hours.ago)