1 files changed, 68 insertions, 0 deletions
diff --git a/spec/lib/gitlab/database/health_status/indicators/write_ahead_log_spec.rb b/spec/lib/gitlab/database/health_status/indicators/write_ahead_log_spec.rb
new file mode 100644
index 00000000000..aa2aee4f94a
--- /dev/null
+++ b/spec/lib/gitlab/database/health_status/indicators/write_ahead_log_spec.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::HealthStatus::Indicators::WriteAheadLog, feature_category: :database do
+  let(:connection) { Gitlab::Database.database_base_models[:main].connection }
+
+  around do |example|
+    Gitlab::Database::SharedModel.using_connection(connection) do
+      example.run
+    end
+  end
+
+  describe '#evaluate' do
+    let(:tables) { [table] }
+    let(:table) { 'users' }
+    let(:context) do
+      Gitlab::Database::HealthStatus::Context.new(
+        described_class,
+        connection,
+        tables,
+        :gitlab_main
+      )
+    end
+
+    subject(:evaluate) { described_class.new(context).evaluate }
+
+    it 'remembers the indicator class' do
+      expect(evaluate.indicator_class).to eq(described_class)
+    end
+
+    it 'returns NoSignal signal in case the feature flag is disabled' do
+      stub_feature_flags(batched_migrations_health_status_wal: false)
+
+      expect(evaluate).to be_a(Gitlab::Database::HealthStatus::Signals::NotAvailable)
+      expect(evaluate.reason).to include('indicator disabled')
+    end
+
+    it 'returns NoSignal signal when WAL archive queue can not be calculated' do
+      expect(connection).to receive(:execute).and_return([{ 'pending_wal_count' => nil }])
+
+      expect(evaluate).to be_a(Gitlab::Database::HealthStatus::Signals::NotAvailable)
+      expect(evaluate.reason).to include('WAL archive queue can not be calculated')
+    end
+
+    it 'uses primary database' do
+      expect(Gitlab::Database::LoadBalancing::Session.current).to receive(:use_primary).and_yield
+
+      evaluate
+    end
+
+    context 'when WAL archive queue size is below the limit' do
+      it 'returns Normal signal' do
+        expect(connection).to receive(:execute).and_return([{ 'pending_wal_count' => 1 }])
+        expect(evaluate).to be_a(Gitlab::Database::HealthStatus::Signals::Normal)
+        expect(evaluate.reason).to include('WAL archive queue is within limit')
+      end
+    end
+
+    context 'when WAL archive queue size is above the limit' do
+      it 'returns Stop signal' do
+        expect(connection).to receive(:execute).and_return([{ 'pending_wal_count' => 420 }])
+        expect(evaluate).to be_a(Gitlab::Database::HealthStatus::Signals::Stop)
+        expect(evaluate.reason).to include('WAL archive queue is too big')
+      end
+    end
+  end
+end