1 files changed, 65 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/exporter/sidekiq_exporter_spec.rb b/spec/lib/gitlab/metrics/exporter/sidekiq_exporter_spec.rb
new file mode 100644
index 00000000000..a415b6407d5
--- /dev/null
+++ b/spec/lib/gitlab/metrics/exporter/sidekiq_exporter_spec.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Metrics::Exporter::SidekiqExporter do
+  let(:exporter) { described_class.new }
+
+  after do
+    exporter.stop
+  end
+
+  context 'with valid config' do
+    before do
+      stub_config(
+        monitoring: {
+          sidekiq_exporter: {
+            enabled: true,
+            port: 0,
+            address: '127.0.0.1'
+          }
+        }
+      )
+    end
+
+    it 'does start thread' do
+      expect(exporter.start).not_to be_nil
+    end
+  end
+
+  context 'when port is already taken' do
+    let(:first_exporter) { described_class.new }
+
+    before do
+      stub_config(
+        monitoring: {
+          sidekiq_exporter: {
+            enabled: true,
+            port: 9992,
+            address: '127.0.0.1'
+          }
+        }
+      )
+
+      first_exporter.start
+    end
+
+    after do
+      first_exporter.stop
+    end
+
+    it 'does print error message' do
+      expect(Sidekiq.logger).to receive(:error)
+        .with(
+          class: described_class.to_s,
+          message: 'Cannot start sidekiq_exporter',
+          exception: anything)
+
+      exporter.start
+    end
+
+    it 'does not start thread' do
+      expect(exporter.start).to be_nil
+    end
+  end
+end