FIX: Event sorting shows oldest events first

plugin.rb

@@ -110,12 +110,17 @@ module ::DiscoursePostEvent
         category = Category.find_by(id: topic_query.options[:category_id])
         if category && category.custom_fields &&
              category.custom_fields["sort_topics_by_event_start_date"]
+          reorder_sql = <<~SQL
+           CASE WHEN COALESCE(custom_fields.value::timestamptz, topics.bumped_at) > NOW() THEN 0 ELSE 1 END,
+           CASE WHEN COALESCE(custom_fields.value::timestamptz, topics.bumped_at) > NOW() THEN COALESCE(custom_fields.value::timestamptz, topics.bumped_at) ELSE NULL END,
+           CASE WHEN COALESCE(custom_fields.value::timestamptz, topics.bumped_at) < NOW() THEN COALESCE(custom_fields.value::timestamptz, topics.bumped_at) ELSE NULL END DESC
+          SQL
           results =
             results.joins(
               "LEFT JOIN topic_custom_fields AS custom_fields on custom_fields.topic_id = topics.id
-            AND custom_fields.name = '#{DiscoursePostEvent::TOPIC_POST_EVENT_STARTS_AT}'
-            ",
-            ).reorder("topics.pinned_at ASC, custom_fields.value ASC")
+         AND custom_fields.name = '#{DiscoursePostEvent::TOPIC_POST_EVENT_STARTS_AT}'
+         ",
+            ).reorder(reorder_sql)
         end
       end
       results

spec/models/topic_query_spec.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+require "rails_helper"
+
+describe TopicQuery do
+  describe "sorts events" do
+    fab!(:user) { Fabricate(:user, admin: true) }
+    fab!(:notified_user) { Fabricate(:user) }
+    fab!(:topic_1) { Fabricate(:topic, user: user) }
+    fab!(:topic_2) { Fabricate(:topic, user: user) }
+    fab!(:topic_3) { Fabricate(:topic, user: user) }
+    fab!(:topic_4) { Fabricate(:topic, user: user) }
+    fab!(:post_1) { Fabricate(:post, topic: topic_1) }
+    fab!(:post_2) { Fabricate(:post, topic: topic_2) }
+    fab!(:post_3) { Fabricate(:post, topic: topic_3) }
+    fab!(:post_4) { Fabricate(:post, topic: topic_4) }
+
+    fab!(:future_event_1) do
+      DiscoursePostEvent::Event.create!(
+        id: post_1.id,
+        original_starts_at: Time.now + 5.hours,
+        original_ends_at: Time.now + 7.hours,
+      )
+    end
+    fab!(:future_event_2) do
+      DiscoursePostEvent::Event.create!(
+        id: post_2.id,
+        original_starts_at: Time.now + 1.hours,
+        original_ends_at: Time.now + 2.hours,
+      )
+    end
+    fab!(:past_event_1) do
+      DiscoursePostEvent::Event.create!(
+        id: post_3.id,
+        original_starts_at: Time.now - 10.hours,
+        original_ends_at: Time.now - 8.hours,
+      )
+    end
+    fab!(:past_event_2) do
+      DiscoursePostEvent::Event.create!(
+        id: post_4.id,
+        original_starts_at: Time.now - 7.hours,
+        original_ends_at: Time.now - 5.hours,
+      )
+    end
+
+    it "upcoming events first, sorted by ascending order. expired events last, sorted by descending order" do
+      ordered_topics =
+        TopicQuery.new(nil, order_by_event_date: [topic_1, topic_2, topic_3, topic_4]).options[
+          :order_by_event_date
+        ]
+      expect(ordered_topics).to eq([topic_1, topic_2, topic_3, topic_4])
+    end
+  end
+end