1 files changed, 252 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/web_transaction_spec.rb b/spec/lib/gitlab/metrics/web_transaction_spec.rb
new file mode 100644
index 00000000000..1d162f53a13
--- /dev/null
+++ b/spec/lib/gitlab/metrics/web_transaction_spec.rb
@@ -0,0 +1,252 @@
+require 'spec_helper'
+
+describe Gitlab::Metrics::WebTransaction do
+  let(:env) { {} }
+  let(:transaction) { described_class.new(env) }
+
+  describe '#duration' do
+    it 'returns the duration of a transaction in seconds' do
+      transaction.run { sleep(0.5) }
+
+      expect(transaction.duration).to be >= 0.5
+    end
+  end
+
+  describe '#allocated_memory' do
+    it 'returns the allocated memory in bytes' do
+      transaction.run { 'a' * 32 }
+
+      expect(transaction.allocated_memory).to be_a_kind_of(Numeric)
+    end
+  end
+
+  describe '#run' do
+    it 'yields the supplied block' do
+      expect { |b| transaction.run(&b) }.to yield_control
+    end
+
+    it 'stores the transaction in the current thread' do
+      transaction.run do
+        expect(Thread.current[described_class::THREAD_KEY]).to eq(transaction)
+      end
+    end
+
+    it 'removes the transaction from the current thread upon completion' do
+      transaction.run { }
+
+      expect(Thread.current[described_class::THREAD_KEY]).to be_nil
+    end
+  end
+
+  describe '#add_metric' do
+    it 'adds a metric to the transaction' do
+      expect(Gitlab::Metrics::Metric).to receive(:new)
+        .with('rails_foo', { number: 10 }, {})
+
+      transaction.add_metric('foo', number: 10)
+    end
+  end
+
+  describe '#method_call_for' do
+    it 'returns a MethodCall' do
+      method = transaction.method_call_for('Foo#bar', :Foo, '#bar')
+
+      expect(method).to be_an_instance_of(Gitlab::Metrics::MethodCall)
+    end
+  end
+
+  describe '#increment' do
+    it 'increments a counter' do
+      transaction.increment(:time, 1)
+      transaction.increment(:time, 2)
+
+      values = { duration: 0.0, time: 3, allocated_memory: a_kind_of(Numeric) }
+
+      expect(transaction).to receive(:add_metric)
+        .with('transactions', values, {})
+
+      transaction.track_self
+    end
+  end
+
+  describe '#set' do
+    it 'sets a value' do
+      transaction.set(:number, 10)
+
+      values = {
+        duration:         0.0,
+        number:           10,
+        allocated_memory: a_kind_of(Numeric)
+      }
+
+      expect(transaction).to receive(:add_metric)
+        .with('transactions', values, {})
+
+      transaction.track_self
+    end
+  end
+
+  describe '#finish' do
+    it 'tracks the transaction details and submits them to Sidekiq' do
+      expect(transaction).to receive(:track_self)
+      expect(transaction).to receive(:submit)
+
+      transaction.finish
+    end
+  end
+
+  describe '#track_self' do
+    it 'adds a metric for the transaction itself' do
+      values = {
+        duration:         transaction.duration,
+        allocated_memory: a_kind_of(Numeric)
+      }
+
+      expect(transaction).to receive(:add_metric)
+        .with('transactions', values, {})
+
+      transaction.track_self
+    end
+  end
+
+  describe '#submit' do
+    it 'submits the metrics to Sidekiq' do
+      transaction.track_self
+
+      expect(Gitlab::Metrics).to receive(:submit_metrics)
+        .with([an_instance_of(Hash)])
+
+      transaction.submit
+    end
+
+    it 'adds the action as a tag for every metric' do
+      allow(transaction).to receive(:labels).and_return(controller: 'Foo', action: 'bar')
+      transaction.track_self
+
+      hash = {
+        series:    'rails_transactions',
+        tags:      { action: 'Foo#bar' },
+        values:    { duration: 0.0, allocated_memory: a_kind_of(Numeric) },
+        timestamp: a_kind_of(Integer)
+      }
+
+      expect(Gitlab::Metrics).to receive(:submit_metrics)
+        .with([hash])
+
+      transaction.submit
+    end
+
+    it 'does not add an action tag for events' do
+      allow(transaction).to receive(:labels).and_return(controller: 'Foo', action: 'bar')
+
+      transaction.add_event(:meow)
+
+      hash = {
+        series:    'events',
+        tags:      { event: :meow },
+        values:    { count: 1 },
+        timestamp: a_kind_of(Integer)
+      }
+
+      expect(Gitlab::Metrics).to receive(:submit_metrics)
+        .with([hash])
+
+      transaction.submit
+    end
+  end
+
+  describe '#labels' do
+    context 'when request goes to Grape endpoint' do
+      before do
+        route = double(:route, request_method: 'GET', path: '/:version/projects/:id/archive(.:format)')
+        endpoint = double(:endpoint, route: route)
+
+        env['api.endpoint'] = endpoint
+      end
+      it 'provides labels with the method and path of the route in the grape endpoint' do
+        expect(transaction.labels).to eq({ controller: 'Grape', action: 'GET /projects/:id/archive' })
+        expect(transaction.action).to eq('Grape#GET /projects/:id/archive')
+      end
+
+      it 'does not provide labels if route infos are missing' do
+        endpoint = double(:endpoint)
+        allow(endpoint).to receive(:route).and_raise
+
+        env['api.endpoint'] = endpoint
+
+        expect(transaction.labels).to eq({})
+        expect(transaction.action).to be_nil
+      end
+    end
+
+    context 'when request goes to ActionController' do
+      let(:content_type) { 'text/html' }
+
+      before do
+        klass = double(:klass, name: 'TestController')
+        controller = double(:controller, class: klass, action_name: 'show', content_type: content_type)
+
+        env['action_controller.instance'] = controller
+      end
+
+      it 'tags a transaction with the name and action of a controller' do
+        expect(transaction.labels).to eq({ controller: 'TestController', action: 'show' })
+        expect(transaction.action).to eq('TestController#show')
+      end
+
+      context 'when the response content type is not :html' do
+        let(:content_type) { 'application/json' }
+
+        it 'appends the mime type to the transaction action' do
+          expect(transaction.labels).to eq({ controller: 'TestController', action: 'show.json' })
+          expect(transaction.action).to eq('TestController#show.json')
+        end
+      end
+    end
+
+    it 'returns no labels when no route information is present in env' do
+      expect(transaction.labels).to eq({})
+      expect(transaction.action).to eq(nil)
+    end
+  end
+
+  describe '#add_event' do
+    it 'adds a metric' do
+      transaction.add_event(:meow)
+
+      expect(transaction.metrics[0]).to be_an_instance_of(Gitlab::Metrics::Metric)
+    end
+
+    it "does not prefix the metric's series name" do
+      transaction.add_event(:meow)
+
+      metric = transaction.metrics[0]
+
+      expect(metric.series).to eq(described_class::EVENT_SERIES)
+    end
+
+    it 'tracks a counter for every event' do
+      transaction.add_event(:meow)
+
+      metric = transaction.metrics[0]
+
+      expect(metric.values).to eq(count: 1)
+    end
+
+    it 'tracks the event name' do
+      transaction.add_event(:meow)
+
+      metric = transaction.metrics[0]
+
+      expect(metric.tags).to eq(event: :meow)
+    end
+
+    it 'allows tracking of custom tags' do
+      transaction.add_event(:meow, animal: 'cat')
+
+      metric = transaction.metrics[0]
+
+      expect(metric.tags).to eq(event: :meow, animal: 'cat')
+    end
+  end
+end