From 0e831b0b692f2988d3c84fc01a463b08afec05ad Mon Sep 17 00:00:00 2001
From: Nick Thomas <nick@gitlab.com>
Date: Wed, 20 Feb 2019 15:35:57 +0000
Subject: Allow external diffs to be used conditionally

Since external diffs are likely to be a bit slower than in-database
ones, add a mode that makes diffs external after they've been obsoleted
by events. This should strike a balance between performance and disk
space.

A background cron drives the majority of migrations, since diffs become
outdated through user actions.
---
 .../migrate_external_diffs_service_spec.rb         | 43 ++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 spec/services/merge_requests/migrate_external_diffs_service_spec.rb

(limited to 'spec/services/merge_requests')

diff --git a/spec/services/merge_requests/migrate_external_diffs_service_spec.rb b/spec/services/merge_requests/migrate_external_diffs_service_spec.rb
new file mode 100644
index 00000000000..40ac747e66f
--- /dev/null
+++ b/spec/services/merge_requests/migrate_external_diffs_service_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe MergeRequests::MigrateExternalDiffsService do
+  let(:merge_request) { create(:merge_request) }
+  let(:diff) { merge_request.merge_request_diff }
+
+  describe '.enqueue!', :sidekiq do
+    around do |example|
+      Sidekiq::Testing.fake! { example.run }
+    end
+
+    it 'enqueues nothing if external diffs are disabled' do
+      expect(diff).not_to be_stored_externally
+
+      expect { described_class.enqueue! }
+        .not_to change { MigrateExternalDiffsWorker.jobs.count }
+    end
+
+    it 'enqueues eligible in-database diffs if external diffs are enabled' do
+      expect(diff).not_to be_stored_externally
+
+      stub_external_diffs_setting(enabled: true)
+
+      expect { described_class.enqueue! }
+        .to change { MigrateExternalDiffsWorker.jobs.count }
+        .by(1)
+    end
+  end
+
+  describe '#execute' do
+    it 'migrates an in-database diff to the external store' do
+      expect(diff).not_to be_stored_externally
+
+      stub_external_diffs_setting(enabled: true)
+
+      described_class.new(diff).execute
+
+      expect(diff).to be_stored_externally
+    end
+  end
+end
-- 
cgit v1.2.1