1 files changed, 62 insertions, 0 deletions
diff --git a/spec/lib/gitlab/memory/watchdog/monitor/unique_memory_growth_spec.rb b/spec/lib/gitlab/memory/watchdog/monitor/unique_memory_growth_spec.rb
new file mode 100644
index 00000000000..22494af4425
--- /dev/null
+++ b/spec/lib/gitlab/memory/watchdog/monitor/unique_memory_growth_spec.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require 'support/shared_examples/lib/gitlab/memory/watchdog/monitor_result_shared_examples'
+require_dependency 'gitlab/cluster/lifecycle_events'
+
+RSpec.describe Gitlab::Memory::Watchdog::Monitor::UniqueMemoryGrowth do
+  let(:primary_memory) { 2048 }
+  let(:worker_memory) { 0 }
+  let(:max_mem_growth) { 2 }
+
+  subject(:monitor) do
+    described_class.new(max_mem_growth: max_mem_growth)
+  end
+
+  before do
+    allow(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).and_return({ uss: worker_memory })
+    allow(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).with(
+      pid: Gitlab::Cluster::PRIMARY_PID
+    ).and_return({ uss: primary_memory })
+  end
+
+  describe '#call' do
+    it 'gets memory_usage_uss_pss' do
+      expect(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).with(no_args)
+      expect(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).with(pid: Gitlab::Cluster::PRIMARY_PID)
+
+      monitor.call
+    end
+
+    context 'when monitor is called twice' do
+      it 'reference memory is calculated only once' do
+        expect(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).with(no_args).twice
+        expect(Gitlab::Metrics::System).to receive(:memory_usage_uss_pss).with(pid: Gitlab::Cluster::PRIMARY_PID).once
+
+        monitor.call
+        monitor.call
+      end
+    end
+
+    context 'when process exceeds threshold' do
+      let(:worker_memory) { max_mem_growth * primary_memory + 1 }
+      let(:payload) do
+        {
+          message: 'memory limit exceeded',
+          memwd_max_uss_bytes: max_mem_growth * primary_memory,
+          memwd_ref_uss_bytes: primary_memory,
+          memwd_uss_bytes: worker_memory
+        }
+      end
+
+      include_examples 'returns Watchdog Monitor result', threshold_violated: true
+    end
+
+    context 'when process does not exceed threshold' do
+      let(:worker_memory) { max_mem_growth * primary_memory - 1 }
+      let(:payload) { {} }
+
+      include_examples 'returns Watchdog Monitor result', threshold_violated: false
+    end
+  end
+end