1 files changed, 121 insertions, 0 deletions
diff --git a/spec/lib/gitlab/memory/watchdog/configuration_spec.rb b/spec/lib/gitlab/memory/watchdog/configuration_spec.rb
new file mode 100644
index 00000000000..892a4b06ad0
--- /dev/null
+++ b/spec/lib/gitlab/memory/watchdog/configuration_spec.rb
@@ -0,0 +1,121 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require_dependency 'gitlab/cluster/lifecycle_events'
+
+RSpec.describe Gitlab::Memory::Watchdog::Configuration do
+  subject(:configuration) { described_class.new }
+
+  describe '#initialize' do
+    it 'initialize monitors' do
+      expect(configuration.monitors).to be_an_instance_of(described_class::MonitorStack)
+    end
+  end
+
+  describe '#handler' do
+    context 'when handler is not set' do
+      it 'defaults to NullHandler' do
+        expect(configuration.handler).to be(Gitlab::Memory::Watchdog::NullHandler.instance)
+      end
+    end
+  end
+
+  describe '#logger' do
+    context 'when logger is not set, defaults to stdout logger' do
+      it 'defaults to Logger' do
+        expect(configuration.logger).to be_an_instance_of(::Gitlab::Logger)
+      end
+    end
+  end
+
+  describe '#sleep_time_seconds' do
+    context 'when sleep_time_seconds is not set' do
+      it 'defaults to SLEEP_TIME_SECONDS' do
+        expect(configuration.sleep_time_seconds).to eq(described_class::DEFAULT_SLEEP_TIME_SECONDS)
+      end
+    end
+  end
+
+  describe '#monitors' do
+    context 'when monitors are configured to be used' do
+      let(:payload1) do
+        {
+          message: 'monitor_1_text',
+          memwd_max_strikes: 5,
+          memwd_cur_strikes: 0
+        }
+      end
+
+      let(:payload2) do
+        {
+          message: 'monitor_2_text',
+          memwd_max_strikes: 0,
+          memwd_cur_strikes: 1
+        }
+      end
+
+      let(:monitor_class_1) do
+        Struct.new(:threshold_violated, :payload) do
+          def call
+            { threshold_violated: !!threshold_violated, payload: payload || {} }
+          end
+
+          def self.name
+            'Monitor1'
+          end
+        end
+      end
+
+      let(:monitor_class_2) do
+        Struct.new(:threshold_violated, :payload) do
+          def call
+            { threshold_violated: !!threshold_violated, payload: payload || {} }
+          end
+
+          def self.name
+            'Monitor2'
+          end
+        end
+      end
+
+      context 'when two monitors are configured to be used' do
+        before do
+          configuration.monitors.use monitor_class_1, false, { message: 'monitor_1_text' }, max_strikes: 5
+          configuration.monitors.use monitor_class_2, true, { message: 'monitor_2_text' }, max_strikes: 0
+        end
+
+        it 'calls each monitor and returns correct results', :aggregate_failures do
+          payloads = []
+          thresholds = []
+          strikes = []
+          monitor_names = []
+
+          configuration.monitors.call_each do |result|
+            payloads << result.payload
+            thresholds << result.threshold_violated?
+            strikes << result.strikes_exceeded?
+            monitor_names << result.monitor_name
+          end
+
+          expect(payloads).to eq([payload1, payload2])
+          expect(thresholds).to eq([false, true])
+          expect(strikes).to eq([false, true])
+          expect(monitor_names).to eq([:monitor1, :monitor2])
+        end
+      end
+
+      context 'when same monitor class is configured to be used twice' do
+        before do
+          configuration.monitors.use monitor_class_1, max_strikes: 1
+          configuration.monitors.use monitor_class_1, max_strikes: 1
+        end
+
+        it 'calls same monitor only once' do
+          expect do |b|
+            configuration.monitors.call_each(&b)
+          end.to yield_control.once
+        end
+      end
+    end
+  end
+end