Only require sidekiq-limit_fetch when enabled in settingsonly-limit-fetch-when-requested

This gem allows Sidekiq jobs to be throttled. Unfortunately, it has a
side-effect: when we haven't enabled job throttling, it will still hit Redis a
lot (and miss, because nothing is configured).

As this setting already required a restart, ensure that the library is only
required when it's enabled.

1 files changed, 33 insertions, 17 deletions

diff --git a/spec/lib/gitlab/sidekiq_throttler_spec.rb b/spec/lib/gitlab/sidekiq_throttler_spec.rb
index 6374ac80207..2dbb7bb7c34 100644
--- a/spec/lib/gitlab/sidekiq_throttler_spec.rb
+++ b/spec/lib/gitlab/sidekiq_throttler_spec.rb
@@ -1,28 +1,44 @@
 require 'spec_helper'
 
 describe Gitlab::SidekiqThrottler do
-  before do
-    Sidekiq.options[:concurrency] = 35
-
-    stub_application_setting(
-      sidekiq_throttling_enabled: true,
-      sidekiq_throttling_factor: 0.1,
-      sidekiq_throttling_queues: %w[build project_cache]
-    )
-  end
-
   describe '#execute!' do
-    it 'sets limits on the selected queues' do
-      described_class.execute!
+    context 'when job throttling is enabled' do
+      before do
+        Sidekiq.options[:concurrency] = 35
+
+        stub_application_setting(
+          sidekiq_throttling_enabled: true,
+          sidekiq_throttling_factor: 0.1,
+          sidekiq_throttling_queues: %w[build project_cache]
+        )
+      end
+
+      it 'requires sidekiq-limit_fetch' do
+        expect(described_class).to receive(:require).with('sidekiq-limit_fetch').and_call_original
+
+        described_class.execute!
+      end
+
+      it 'sets limits on the selected queues' do
+        described_class.execute!
+
+        expect(Sidekiq::Queue['build'].limit).to eq 4
+        expect(Sidekiq::Queue['project_cache'].limit).to eq 4
+      end
+
+      it 'does not set limits on other queues' do
+        described_class.execute!
 
-      expect(Sidekiq::Queue['build'].limit).to eq 4
-      expect(Sidekiq::Queue['project_cache'].limit).to eq 4
+        expect(Sidekiq::Queue['merge'].limit).to be_nil
+      end
     end
 
-    it 'does not set limits on other queues' do
-      described_class.execute!
+    context 'when job throttling is disabled' do
+      it 'does not require sidekiq-limit_fetch' do
+        expect(described_class).not_to receive(:require).with('sidekiq-limit_fetch')
 
-      expect(Sidekiq::Queue['merge'].limit).to be_nil
+        described_class.execute!
+      end
     end
   end
 end