From 8650f5c5aa7dbf1bda5d93887f4e88727991d58e Mon Sep 17 00:00:00 2001
From: Molly Struve <mollylbs@gmail.com>
Date: Tue, 31 Dec 2019 14:14:23 -0500
Subject: [PATCH] Create new BustCacheWorker and start sending jobs to it
 (#5302) [deploy]

---
 app/models/article.rb                         |  2 +-
 app/workers/articles/bust_cache_worker.rb     | 13 ++++++
 spec/rails_helper.rb                          |  1 +
 .../articles/bust_cache_worker_spec.rb        | 46 +++++++++++++++++++
 .../enqueues_on_correct_queue.rb              | 11 +++++
 5 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 app/workers/articles/bust_cache_worker.rb
 create mode 100644 spec/workers/articles/bust_cache_worker_spec.rb
 create mode 100644 spec/workers/shared_examples/enqueues_on_correct_queue.rb

diff --git a/app/models/article.rb b/app/models/article.rb
index bac8faf3b..3c4fe8709 100644
--- a/app/models/article.rb
+++ b/app/models/article.rb
@@ -647,6 +647,6 @@ class Article < ApplicationRecord
   end
 
   def async_bust
-    Articles::BustCacheJob.perform_later(id)
+    Articles::BustCacheWorker.perform_async(id)
   end
 end
diff --git a/app/workers/articles/bust_cache_worker.rb b/app/workers/articles/bust_cache_worker.rb
new file mode 100644
index 000000000..e1876e996
--- /dev/null
+++ b/app/workers/articles/bust_cache_worker.rb
@@ -0,0 +1,13 @@
+module Articles
+  class BustCacheWorker
+    include Sidekiq::Worker
+
+    sidekiq_options queue: :high_priority, retry: 10
+
+    def perform(article_id, cache_buster = "CacheBuster")
+      article = Article.find_by(id: article_id)
+
+      cache_buster.constantize.bust_article(article) if article
+    end
+  end
+end
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index f1f046be6..9bbb49cb4 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -33,6 +33,7 @@ Dir[Rails.root.join("spec/support/**/*.rb")].sort.each { |f| require f }
 Dir[Rails.root.join("spec/system/shared_examples/**/*.rb")].sort.each { |f| require f }
 Dir[Rails.root.join("spec/models/shared_examples/**/*.rb")].sort.each { |f| require f }
 Dir[Rails.root.join("spec/jobs/shared_examples/**/*.rb")].sort.each { |f| require f }
+Dir[Rails.root.join("spec/workers/shared_examples/**/*.rb")].sort.each { |f| require f }
 
 # Checks for pending migrations before tests are run.
 # If you are not using ActiveRecord, you can remove this line.
diff --git a/spec/workers/articles/bust_cache_worker_spec.rb b/spec/workers/articles/bust_cache_worker_spec.rb
new file mode 100644
index 000000000..83dd19f0a
--- /dev/null
+++ b/spec/workers/articles/bust_cache_worker_spec.rb
@@ -0,0 +1,46 @@
+require "rails_helper"
+
+class NewBuster
+  def self.bust_article(*); end
+end
+
+RSpec.describe Articles::BustCacheWorker, type: :worker do
+  include_examples "#enqueues_on_correct_queue", "high_priority", 1
+
+  describe "#perform" do
+    let(:worker) { subject }
+
+    context "with article" do
+      let(:article) { double }
+      let(:article_id) { 1 }
+
+      before do
+        allow(Article).to receive(:find_by).with(id: article_id).and_return(article)
+      end
+
+      it "with cache buster defined busts cache with defined buster" do
+        allow(NewBuster).to receive(:bust_article)
+        worker.perform(article_id, "NewBuster")
+        expect(NewBuster).to have_received(:bust_article).with(article)
+      end
+
+      it "without cache buster defined busts cache with default" do
+        allow(CacheBuster).to receive(:bust_article)
+        worker.perform(article_id)
+        expect(CacheBuster).to have_received(:bust_article).with(article)
+      end
+    end
+
+    context "without article" do
+      it "does not error" do
+        expect { worker.perform(nil, "CacheBuster") }.not_to raise_error
+      end
+
+      it "does not bust cache" do
+        allow(CacheBuster).to receive(:bust_article)
+        worker.perform(nil)
+        expect(CacheBuster).not_to have_received(:bust_article)
+      end
+    end
+  end
+end
diff --git a/spec/workers/shared_examples/enqueues_on_correct_queue.rb b/spec/workers/shared_examples/enqueues_on_correct_queue.rb
new file mode 100644
index 000000000..badb8b37f
--- /dev/null
+++ b/spec/workers/shared_examples/enqueues_on_correct_queue.rb
@@ -0,0 +1,11 @@
+RSpec.shared_examples "#enqueues_on_correct_queue" do |queue_name, args|
+  describe "#perform_async" do
+    it "enqueues the job" do
+      Sidekiq::Testing.fake!
+
+      expect do
+        described_class.perform_async(args)
+      end.to change { Sidekiq::Queues[queue_name].size }.by(1)
+    end
+  end
+end