1 files changed, 71 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb b/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb
new file mode 100644
index 00000000000..e01b0b4bd21
--- /dev/null
+++ b/spec/lib/gitlab/metrics/subscribers/rails_cache_spec.rb
@@ -0,0 +1,71 @@
+require 'spec_helper'
+
+describe Gitlab::Metrics::Subscribers::RailsCache do
+  let(:transaction) { Gitlab::Metrics::Transaction.new }
+  let(:subscriber) { described_class.new }
+
+  let(:event) { double(:event, duration: 15.2) }
+
+  describe '#cache_read' do
+    it 'increments the cache_read duration' do
+      expect(subscriber).to receive(:increment).
+        with(:cache_read_duration, event.duration)
+
+      subscriber.cache_read(event)
+    end
+  end
+
+  describe '#cache_write' do
+    it 'increments the cache_write duration' do
+      expect(subscriber).to receive(:increment).
+        with(:cache_write_duration, event.duration)
+
+      subscriber.cache_write(event)
+    end
+  end
+
+  describe '#cache_delete' do
+    it 'increments the cache_delete duration' do
+      expect(subscriber).to receive(:increment).
+        with(:cache_delete_duration, event.duration)
+
+      subscriber.cache_delete(event)
+    end
+  end
+
+  describe '#cache_exist?' do
+    it 'increments the cache_exists duration' do
+      expect(subscriber).to receive(:increment).
+        with(:cache_exists_duration, event.duration)
+
+      subscriber.cache_exist?(event)
+    end
+  end
+
+  describe '#increment' do
+    context 'without a transaction' do
+      it 'returns' do
+        expect(transaction).not_to receive(:increment)
+
+        subscriber.increment(:foo, 15.2)
+      end
+    end
+
+    context 'with a transaction' do
+      before do
+        allow(subscriber).to receive(:current_transaction).
+          and_return(transaction)
+      end
+
+      it 'increments the total and specific cache duration' do
+        expect(transaction).to receive(:increment).
+          with(:cache_duration, event.duration)
+
+        expect(transaction).to receive(:increment).
+          with(:cache_delete_duration, event.duration)
+
+        subscriber.increment(:cache_delete_duration, event.duration)
+      end
+    end
+  end
+end