From f86f93bc8ab796fee1a6a1b58fdbace87e8b5152 Mon Sep 17 00:00:00 2001
From: Molly Struve <mollylbs@gmail.com>
Date: Thu, 26 Dec 2019 13:17:34 -0600
Subject: [PATCH] Create rake Task to Destroy Old Notifications (#5180)
 [deploy]

---
 app/models/notification.rb       |  4 ++++
 lib/tasks/fetch.rake             |  4 ++--
 spec/factories/notifications.rb  |  3 +++
 spec/models/notification_spec.rb | 13 +++++++++++++
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/app/models/notification.rb b/app/models/notification.rb
index 5c93072ea..2635bd487 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -136,6 +136,10 @@ class Notification < ApplicationRecord
       Notifications::UpdateJob.perform_later(notifiable.id, notifiable.class.name, action)
     end
 
+    def fast_destroy_old_notifications(destroy_before_timestamp = 4.months.ago)
+      Notification.where("created_at < ?", destroy_before_timestamp).in_batches(of: 10_000).delete_all
+    end
+
     private
 
     def user_data(user)
diff --git a/lib/tasks/fetch.rake b/lib/tasks/fetch.rake
index a42f3d7e1..99b5e2821 100644
--- a/lib/tasks/fetch.rake
+++ b/lib/tasks/fetch.rake
@@ -37,8 +37,8 @@ task expire_old_listings: :environment do
   end
 end
 
-task clear_memory_if_too_high: :environment do
-  Rails.cache.clear if Rails.cache.stats.flatten[1]["bytes"].to_i > 9_650_000_000
+task remove_old_notifications: :environment do
+  Notification.fast_destroy_old_notifications
 end
 
 task save_nil_hotness_scores: :environment do
diff --git a/spec/factories/notifications.rb b/spec/factories/notifications.rb
index d3a3c977a..35ae1b786 100644
--- a/spec/factories/notifications.rb
+++ b/spec/factories/notifications.rb
@@ -1,4 +1,7 @@
 FactoryBot.define do
   factory :notification do
+    association :user, factory: :user, strategy: :create
+    association :organization, factory: :organization, strategy: :create
+    notifiable { create(:article) }
   end
 end
diff --git a/spec/models/notification_spec.rb b/spec/models/notification_spec.rb
index b0f426b48..e3ac9e96d 100644
--- a/spec/models/notification_spec.rb
+++ b/spec/models/notification_spec.rb
@@ -517,4 +517,17 @@ RSpec.describe Notification, type: :model do
       end
     end
   end
+
+  describe "#fast_destroy_old_notifications" do
+    it "bulk deletes notifications older than 4 months by default" do
+      create_list :notification, 5
+      described_class.last.update(created_at: 5.months.ago)
+      expect { described_class.fast_destroy_old_notifications }.to change(described_class, :count).by(-1)
+    end
+
+    it "bulk deletes notifications older than a given timestamp" do
+      create_list :notification, 5
+      expect { described_class.fast_destroy_old_notifications(Time.zone.now) }.to change(described_class, :count).by(-5)
+    end
+  end
 end