DEV: add modifier to reminder assigned topics query (#565)

* FEATURE: Prevents assign notification

Relates to this [topic](https://meta.discourse.org/t/assign-plugin-for-informatica/256974/94)

* DEV: Add tests to assigns_reminder_assigned_topics_query modifier

* DEV: lint pending_assigns_reminder_spec.rb

* DEV: Address review feedback

Remove puts from test.

lib/pending_assigns_reminder.rb

@@ -67,6 +67,7 @@ class PendingAssignsReminder
     secure =
       Topic.listable_topics.secured(Guardian.new(user)).or(Topic.private_messages_for_user(user))
 
+    topics =
       Topic
         .joins(:assignment)
         .select(:slug, :id, :title, :fancy_title, "assignments.created_at AS assigned_at")
@@ -74,9 +75,8 @@ class PendingAssignsReminder
           "assignments.assigned_to_id = ? AND assignments.assigned_to_type = 'User' AND assignments.active",
           user.id,
         )
-      .merge(secure)
+    topics = DiscoursePluginRegistry.apply_modifier(:assigns_reminder_assigned_topics_query, topics)
-      .order("assignments.created_at #{order}")
+    topics.merge(secure).order("assignments.created_at #{order}").limit(3)
-      .limit(3)
   end
 
   def reminder_body(user, assigned_topics_count, first_three_topics, last_three_topics)

spec/lib/pending_assigns_reminder_spec.rb

@@ -142,5 +142,21 @@ RSpec.describe PendingAssignsReminder do
 
       expect(topic.title).to eq(I18n.t("pending_assigns_reminder.title", pending_assignments: 3))
     end
+
+    context "with assigns_reminder_assigned_topics_query" do
+      let(:modifier_block) { Proc.new { |query| query.where.not(id: @post1.topic_id) } }
+      it "doesn't remind if topic is solved" do
+        plugin_instance = Plugin::Instance.new
+        plugin_instance.register_modifier(:assigns_reminder_assigned_topics_query, &modifier_block)
+        topics = reminder.send(:assigned_topics, user, order: :asc)
+        expect(topics).not_to include(@post1.topic)
+      ensure
+        DiscoursePluginRegistry.unregister_modifier(
+          plugin_instance,
+          :assigns_reminder_assigned_topics_query,
+          &modifier_block
+        )
+      end
+    end
   end
 end