From 74f71503249ecbfc8b4e29c34807963ddd650dfa Mon Sep 17 00:00:00 2001
From: Andrei Prigorshnev <a.prigorshnev@gmail.com>
Date: Fri, 28 May 2021 17:33:10 +0400
Subject: [PATCH] FEATURE: Automatically timed delete stub topics after entire
 topic is merged into another topic (#13187)

When a topic is fully merged into another topic we close it. Now we want also to set a timer for deleting this topic. By default, stub topics will be deleted in 7 days. Users can change this period or disable auto-deleting by setting the period to 0.
---
 app/models/post_mover.rb       | 15 +++++++++-
 config/locales/server.en.yml   |  1 +
 config/site_settings.yml       |  4 +++
 spec/models/post_mover_spec.rb | 53 ++++++++++++++++++++++++++++++++--
 4 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/app/models/post_mover.rb b/app/models/post_mover.rb
index 27a352738e6..bedd483978b 100644
--- a/app/models/post_mover.rb
+++ b/app/models/post_mover.rb
@@ -79,7 +79,7 @@ class PostMover
     update_bookmarks
 
     if moving_all_posts
-      @original_topic.update_status('closed', true, @user)
+      close_topic_and_schedule_deletion
     end
 
     destination_topic.reload
@@ -546,4 +546,17 @@ class PostMover
       topic_id: topic.id
     )
   end
+
+  def close_topic_and_schedule_deletion
+    @original_topic.update_status('closed', true, @user)
+
+    days_to_deleting = SiteSetting.delete_merged_stub_topics_after_days
+    if days_to_deleting > 0
+      @original_topic.set_or_create_timer(
+        TopicTimer.types[:delete],
+        days_to_deleting * 24,
+        by_user: @user
+      )
+    end
+  end
 end
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 6db98692d13..e56cd63c50d 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -2185,6 +2185,7 @@ en:
     show_create_topics_notice: "If the site has fewer than 5 public topics, show a notice asking admins to create some topics."
 
     delete_drafts_older_than_n_days: "Delete drafts older than (n) days."
+    delete_merged_stub_topics_after_days: "Number of days to wait before automatically deleting fully merged stub topics. Set to 0 to never delete stub topics."
 
     bootstrap_mode_min_users: "Minimum number of users required to disable bootstrap mode (set to 0 to disable)"
 
diff --git a/config/site_settings.yml b/config/site_settings.yml
index 1672d579d0e..5c2ef5daac6 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -2146,6 +2146,10 @@ uncategorized:
     default: 180
     max: 36500
 
+  delete_merged_stub_topics_after_days:
+    default: 7
+    min: 0
+
   backup_drafts_to_pm_length:
     default: 0
     hidden: true
diff --git a/spec/models/post_mover_spec.rb b/spec/models/post_mover_spec.rb
index 2729981a399..05220dd93fa 100644
--- a/spec/models/post_mover_spec.rb
+++ b/spec/models/post_mover_spec.rb
@@ -608,11 +608,60 @@ describe PostMover do
 
           it "moving all posts will close the topic" do
             topic.expects(:add_moderator_post).twice
-            moved_to = topic.move_posts(user, [p1.id, p2.id, p3.id, p4.id], destination_topic_id: destination_topic.id)
+            posts_to_move = [p1.id, p2.id, p3.id, p4.id]
+            moved_to = topic.move_posts(user, posts_to_move, destination_topic_id: destination_topic.id)
             expect(moved_to).to be_present
 
             topic.reload
-            expect(topic.closed).to eq(true)
+            expect(topic).to be_closed
+          end
+
+          it "doesn't close the topic when not all posts were moved" do
+            topic.expects(:add_moderator_post).once
+            posts_to_move = [p1.id, p2.id, p3.id]
+            moved_to = topic.move_posts(user, posts_to_move, destination_topic_id: destination_topic.id)
+            expect(moved_to).to be_present
+
+            topic.reload
+            expect(topic).to_not be_closed
+          end
+
+          it "schedules topic deleting when all posts were moved" do
+            SiteSetting.delete_merged_stub_topics_after_days = 7
+            freeze_time
+
+            topic.expects(:add_moderator_post).twice
+            posts_to_move = [p1.id, p2.id, p3.id, p4.id]
+            moved_to = topic.move_posts(user, posts_to_move, destination_topic_id: destination_topic.id)
+            expect(moved_to).to be_present
+
+            timer = topic.topic_timers.find_by(status_type: TopicTimer.types[:delete])
+            expect(timer).to be_present
+            expect(timer.execute_at).to eq_time(7.days.from_now)
+          end
+
+          it "doesn't schedule topic deleting when not all posts were moved" do
+            SiteSetting.delete_merged_stub_topics_after_days = 7
+
+            topic.expects(:add_moderator_post).once
+            posts_to_move = [p1.id, p2.id, p3.id]
+            moved_to = topic.move_posts(user, posts_to_move, destination_topic_id: destination_topic.id)
+            expect(moved_to).to be_present
+
+            timer = topic.topic_timers.find_by(status_type: TopicTimer.types[:delete])
+            expect(timer).to be_nil
+          end
+
+          it "doesn't schedule topic deleting when all posts were moved if it's disabled in settings" do
+            SiteSetting.delete_merged_stub_topics_after_days = 0
+
+            topic.expects(:add_moderator_post).twice
+            posts_to_move = [p1.id, p2.id, p3.id, p4.id]
+            moved_to = topic.move_posts(user, posts_to_move, destination_topic_id: destination_topic.id)
+            expect(moved_to).to be_present
+
+            timer = topic.topic_timers.find_by(status_type: TopicTimer.types[:delete])
+            expect(timer).to be_nil
           end
 
           it "does not try to move small action posts" do