1 files changed, 63 insertions, 0 deletions
diff --git a/spec/lib/gitlab/health_checks/unicorn_check_spec.rb b/spec/lib/gitlab/health_checks/unicorn_check_spec.rb
new file mode 100644
index 00000000000..c02d0c37738
--- /dev/null
+++ b/spec/lib/gitlab/health_checks/unicorn_check_spec.rb
@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+describe Gitlab::HealthChecks::UnicornCheck do
+  let(:result_class) { Gitlab::HealthChecks::Result }
+  let(:readiness) { described_class.readiness }
+  let(:metrics) { described_class.metrics }
+
+  before do
+    described_class.clear_memoization(:http_servers)
+  end
+
+  shared_examples 'with state' do |(state, message)|
+    it "does provide readiness" do
+      expect(readiness).to eq(result_class.new('unicorn_check', state, message))
+    end
+
+    it "does provide metrics" do
+      expect(metrics).to include(
+        an_object_having_attributes(name: 'unicorn_check_success', value: state ? 1 : 0))
+      expect(metrics).to include(
+        an_object_having_attributes(name: 'unicorn_check_latency_seconds', value: be >= 0))
+    end
+  end
+
+  context 'when Unicorn is not loaded' do
+    before do
+      hide_const('Unicorn')
+    end
+
+    it "does not provide readiness and metrics" do
+      expect(readiness).to be_nil
+      expect(metrics).to be_nil
+    end
+  end
+
+  context 'when Unicorn is loaded' do
+    let(:http_server_class) { Struct.new(:worker_processes) }
+
+    before do
+      stub_const('Unicorn::HttpServer', http_server_class)
+    end
+
+    context 'when no servers are running' do
+      it_behaves_like 'with state', [false, 'unexpected Unicorn check result: 0']
+    end
+
+    context 'when servers without workers are running' do
+      before do
+        http_server_class.new(0)
+      end
+
+      it_behaves_like 'with state', [false, 'unexpected Unicorn check result: 0']
+    end
+
+    context 'when servers with workers are running' do
+      before do
+        http_server_class.new(1)
+      end
+
+      it_behaves_like 'with state', true
+    end
+  end
+end