Add retention policy for cached content and media (#19232)

spec/lib/vacuum/feeds_vacuum_spec.rb

@@ -0,0 +1,30 @@
+require 'rails_helper'
+
+RSpec.describe Vacuum::FeedsVacuum do
+  subject { described_class.new }
+
+  describe '#perform' do
+    let!(:active_user) { Fabricate(:user, current_sign_in_at: 2.days.ago) }
+    let!(:inactive_user) { Fabricate(:user, current_sign_in_at: 22.days.ago) }
+
+    before do
+      redis.zadd(feed_key_for(inactive_user), 1, 1)
+      redis.zadd(feed_key_for(active_user), 1, 1)
+      redis.zadd(feed_key_for(inactive_user, 'reblogs'), 2, 2)
+      redis.sadd(feed_key_for(inactive_user, 'reblogs:2'), 3)
+
+      subject.perform
+    end
+
+    it 'clears feeds of inactive users and lists' do
+      expect(redis.zcard(feed_key_for(inactive_user))).to eq 0
+      expect(redis.zcard(feed_key_for(active_user))).to eq 1
+      expect(redis.exists?(feed_key_for(inactive_user, 'reblogs'))).to be false
+      expect(redis.exists?(feed_key_for(inactive_user, 'reblogs:2'))).to be false
+    end
+  end
+
+  def feed_key_for(user, subtype = nil)
+    FeedManager.instance.key(:home, user.account_id, subtype)
+  end
+end