1 files changed, 63 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/rack_middleware_spec.rb b/spec/lib/gitlab/metrics/rack_middleware_spec.rb
new file mode 100644
index 00000000000..a143fe4cfcd
--- /dev/null
+++ b/spec/lib/gitlab/metrics/rack_middleware_spec.rb
@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+describe Gitlab::Metrics::RackMiddleware do
+  let(:app) { double(:app) }
+
+  let(:middleware) { described_class.new(app) }
+
+  let(:env) { { 'REQUEST_METHOD' => 'GET', 'REQUEST_URI' => '/foo' } }
+
+  describe '#call' do
+    before do
+      expect_any_instance_of(Gitlab::Metrics::Transaction).to receive(:finish)
+    end
+
+    it 'tracks a transaction' do
+      expect(app).to receive(:call).with(env).and_return('yay')
+
+      expect(middleware.call(env)).to eq('yay')
+    end
+
+    it 'tags a transaction with the name and action of a controller' do
+      klass      = double(:klass, name: 'TestController')
+      controller = double(:controller, class: klass, action_name: 'show')
+
+      env['action_controller.instance'] = controller
+
+      allow(app).to receive(:call).with(env)
+
+      expect(middleware).to receive(:tag_controller).
+        with(an_instance_of(Gitlab::Metrics::Transaction), env)
+
+      middleware.call(env)
+    end
+  end
+
+  describe '#transaction_from_env' do
+    let(:transaction) { middleware.transaction_from_env(env) }
+
+    it 'returns a Transaction' do
+      expect(transaction).to be_an_instance_of(Gitlab::Metrics::Transaction)
+    end
+
+    it 'tags the transaction with the request method and URI' do
+      expect(transaction.tags[:request_method]).to eq('GET')
+      expect(transaction.tags[:request_uri]).to eq('/foo')
+    end
+  end
+
+  describe '#tag_controller' do
+    let(:transaction) { middleware.transaction_from_env(env) }
+
+    it 'tags a transaction with the name and action of a controller' do
+      klass      = double(:klass, name: 'TestController')
+      controller = double(:controller, class: klass, action_name: 'show')
+
+      env['action_controller.instance'] = controller
+
+      middleware.tag_controller(transaction, env)
+
+      expect(transaction.tags[:action]).to eq('TestController#show')
+    end
+  end
+end