Cache spec check if prometheus metrics are triggered

spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb

@@ -33,6 +33,12 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
           subscriber.cache_read(event)
         end
 
+        it 'increments the cache_read_hit total' do
+          expect(described_class.metric_cache_read_hit_total).to receive(:increment)
+
+          subscriber.cache_read(event)
+        end
+
         context 'when super operation is fetch' do
           let(:event) { double(:event, duration: 15.2, payload: { hit: true, super_operation: :fetch }) }
 
@@ -57,6 +63,12 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
           subscriber.cache_read(event)
         end
 
+        it 'increments the cache_read_miss total' do
+          expect(described_class.metric_cache_read_miss_total).to receive(:increment)
+
+          subscriber.cache_read(event)
+        end
+
         context 'when super operation is fetch' do
           let(:event) { double(:event, duration: 15.2, payload: { hit: false, super_operation: :fetch }) }
 
@@ -72,7 +84,7 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
   end
 
   describe '#cache_write' do
-    it 'increments the cache_write duration' do
+    it 'observes write duration' do
       expect(subscriber).to receive(:observe)
                               .with(:write, event.duration)
 
@@ -81,7 +93,7 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
   end
 
   describe '#cache_delete' do
-    it 'increments the cache_delete duration' do
+    it 'observes delete duration' do
       expect(subscriber).to receive(:observe)
                               .with(:delete, event.duration)
 
@@ -90,7 +102,7 @@ describe Gitlab::Metrics::Subscribers::RailsCache do
   end
 
   describe '#cache_exist?' do
-    it 'increments the cache_exists duration' do
+    it 'observes the exists duration' do
       expect(subscriber).to receive(:observe)
                               .with(:exists, event.duration)