1 files changed, 144 insertions, 0 deletions
diff --git a/spec/lib/gitlab/instrumentation/redis_base_spec.rb b/spec/lib/gitlab/instrumentation/redis_base_spec.rb
new file mode 100644
index 00000000000..5ea8f00114e
--- /dev/null
+++ b/spec/lib/gitlab/instrumentation/redis_base_spec.rb
@@ -0,0 +1,144 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Instrumentation::RedisBase, :request_store do
+  let(:instrumentation_class_a) do
+    stub_const('InstanceA', Class.new(described_class))
+  end
+
+  let(:instrumentation_class_b) do
+    stub_const('InstanceB', Class.new(described_class))
+  end
+
+  describe '.storage_key' do
+    it 'returns the class name with underscore' do
+      expect(instrumentation_class_a.storage_key).to eq('instance_a')
+      expect(instrumentation_class_b.storage_key).to eq('instance_b')
+    end
+  end
+
+  describe '.known_payload_keys' do
+    it 'returns generated payload keys' do
+      expect(instrumentation_class_a.known_payload_keys).to eq([:redis_instance_a_calls,
+                                                                :redis_instance_a_duration_s,
+                                                                :redis_instance_a_read_bytes,
+                                                                :redis_instance_a_write_bytes])
+    end
+
+    it 'does not call calculation methods' do
+      expect(instrumentation_class_a).not_to receive(:get_request_count)
+      expect(instrumentation_class_a).not_to receive(:query_time)
+      expect(instrumentation_class_a).not_to receive(:read_bytes)
+      expect(instrumentation_class_a).not_to receive(:write_bytes)
+
+      instrumentation_class_a.known_payload_keys
+    end
+  end
+
+  describe '.payload' do
+    it 'returns values that are higher than 0' do
+      allow(instrumentation_class_a).to receive(:get_request_count) { 1 }
+      allow(instrumentation_class_a).to receive(:query_time) { 0.1 }
+      allow(instrumentation_class_a).to receive(:read_bytes) { 0.0 }
+      allow(instrumentation_class_a).to receive(:write_bytes) { 123 }
+
+      expected_payload = {
+        redis_instance_a_calls: 1,
+        redis_instance_a_write_bytes: 123,
+        redis_instance_a_duration_s: 0.1
+      }
+
+      expect(instrumentation_class_a.payload).to eq(expected_payload)
+    end
+  end
+
+  describe '.add_duration' do
+    it 'does not lose precision while adding' do
+      precision = 1.0 / (10**::Gitlab::InstrumentationHelper::DURATION_PRECISION)
+      2.times { instrumentation_class_a.add_duration(0.4 * precision) }
+
+      # 2 * 0.4 should be 0.8 and get rounded to 1
+      expect(instrumentation_class_a.query_time).to eq(1 * precision)
+    end
+
+    context 'storage key overlapping' do
+      it 'keys do not overlap across storages' do
+        instrumentation_class_a.add_duration(0.4)
+        instrumentation_class_b.add_duration(0.5)
+
+        expect(instrumentation_class_a.query_time).to eq(0.4)
+        expect(instrumentation_class_b.query_time).to eq(0.5)
+      end
+    end
+  end
+
+  describe '.increment_request_count' do
+    context 'storage key overlapping' do
+      it 'keys do not overlap across storages' do
+        3.times { instrumentation_class_a.increment_request_count }
+        2.times { instrumentation_class_b.increment_request_count }
+
+        expect(instrumentation_class_a.get_request_count).to eq(3)
+        expect(instrumentation_class_b.get_request_count).to eq(2)
+      end
+    end
+  end
+
+  describe '.increment_write_bytes' do
+    context 'storage key overlapping' do
+      it 'keys do not overlap across storages' do
+        2.times do
+          instrumentation_class_a.increment_write_bytes(42)
+          instrumentation_class_b.increment_write_bytes(77)
+        end
+
+        expect(instrumentation_class_a.write_bytes).to eq(42 * 2)
+        expect(instrumentation_class_b.write_bytes).to eq(77 * 2)
+      end
+    end
+  end
+
+  describe '.increment_read_bytes' do
+    context 'storage key overlapping' do
+      it 'keys do not overlap across storages' do
+        2.times do
+          instrumentation_class_a.increment_read_bytes(42)
+          instrumentation_class_b.increment_read_bytes(77)
+        end
+
+        expect(instrumentation_class_a.read_bytes).to eq(42 * 2)
+        expect(instrumentation_class_b.read_bytes).to eq(77 * 2)
+      end
+    end
+  end
+
+  describe '.add_call_details' do
+    before do
+      allow(Gitlab::PerformanceBar).to receive(:enabled_for_request?) { true }
+    end
+
+    context 'storage key overlapping' do
+      it 'keys do not overlap across storages' do
+        2.times do
+          instrumentation_class_a.add_call_details(0.3, [:set])
+          instrumentation_class_b.add_call_details(0.4, [:set])
+        end
+
+        expect(instrumentation_class_a.detail_store).to match(
+          [
+            a_hash_including(cmd: :set, duration: 0.3, backtrace: an_instance_of(Array)),
+            a_hash_including(cmd: :set, duration: 0.3, backtrace: an_instance_of(Array))
+          ]
+        )
+
+        expect(instrumentation_class_b.detail_store).to match(
+          [
+            a_hash_including(cmd: :set, duration: 0.4, backtrace: an_instance_of(Array)),
+            a_hash_including(cmd: :set, duration: 0.4, backtrace: an_instance_of(Array))
+          ]
+        )
+      end
+    end
+  end
+end