1 files changed, 57 insertions, 0 deletions
diff --git a/spec/lib/gitlab/usage_data_counters/aggregated_metrics_spec.rb b/spec/lib/gitlab/usage_data_counters/aggregated_metrics_spec.rb
new file mode 100644
index 00000000000..e9fb5346eae
--- /dev/null
+++ b/spec/lib/gitlab/usage_data_counters/aggregated_metrics_spec.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'aggregated metrics' do
+  RSpec::Matchers.define :be_known_event do
+    match do |event|
+      Gitlab::UsageDataCounters::HLLRedisCounter.known_event?(event)
+    end
+
+    failure_message do
+      "Event with name: `#{event}` can not be found within `#{Gitlab::UsageDataCounters::HLLRedisCounter::KNOWN_EVENTS_PATH}`"
+    end
+  end
+
+  let_it_be(:known_events) do
+    Gitlab::UsageDataCounters::HLLRedisCounter.known_events
+  end
+
+  Gitlab::UsageDataCounters::HLLRedisCounter.aggregated_metrics.tap do |aggregated_metrics|
+    it 'all events has unique name' do
+      event_names = aggregated_metrics&.map { |event| event[:name] }
+
+      expect(event_names).to eq(event_names&.uniq)
+    end
+
+    aggregated_metrics&.each do |aggregate|
+      context "for #{aggregate[:name]} aggregate of #{aggregate[:events].join(' ')}" do
+        let_it_be(:events_records) { known_events.select { |event| aggregate[:events].include?(event[:name]) } }
+
+        it "only refers to known events" do
+          expect(aggregate[:events]).to all be_known_event
+        end
+
+        it "has expected structure" do
+          expect(aggregate.keys).to include(*%w[name operator events])
+        end
+
+        it "uses allowed aggregation operators" do
+          expect(Gitlab::UsageDataCounters::HLLRedisCounter::ALLOWED_METRICS_AGGREGATIONS).to include aggregate[:operator]
+        end
+
+        it "uses events from the same Redis slot" do
+          event_slots = events_records.map { |event| event[:redis_slot] }.uniq
+
+          expect(event_slots).to contain_exactly(be_present)
+        end
+
+        it "uses events with the same aggregation period" do
+          event_slots = events_records.map { |event| event[:aggregation] }.uniq
+
+          expect(event_slots).to contain_exactly(be_present)
+        end
+      end
+    end
+  end
+end