Extract snowplow tracker into separate class

To prepare for sending events to multiple destinations

lib/gitlab/tracking.rb

 # frozen_string_literal: true
 
-require 'snowplow-tracker'
-
 module Gitlab
   module Tracking
     SNOWPLOW_NAMESPACE = 'gl'
@@ -27,16 +25,11 @@ module Gitlab
       end
 
       def event(category, action, label: nil, property: nil, value: nil, context: nil)
-        return unless enabled?
-
-        snowplow.track_struct_event(category, action, label, property, value, context, (Time.now.to_f * 1000).to_i)
+        snowplow.event(category, action, label: label, property: property, value: value, context: context)
       end
 
       def self_describing_event(schema_url, event_data_json, context: nil)
-        return unless enabled?
-
-        event_json = SnowplowTracker::SelfDescribingJson.new(schema_url, event_data_json)
-        snowplow.track_self_describing_event(event_json, context, (Time.now.to_f * 1000).to_i)
+        snowplow.self_describing_event(schema_url, event_data_json, context: context)
       end
 
       def snowplow_options(group)
@@ -54,19 +47,7 @@ module Gitlab
       private
 
       def snowplow
-        @snowplow ||= SnowplowTracker::Tracker.new(
-          emitter,
-          SnowplowTracker::Subject.new,
-          SNOWPLOW_NAMESPACE,
-          Gitlab::CurrentSettings.snowplow_app_id
-        )
-      end
-
-      def emitter
-        SnowplowTracker::AsyncEmitter.new(
-          Gitlab::CurrentSettings.snowplow_collector_hostname,
-          protocol: 'https'
-        )
+        @snowplow ||= Gitlab::Tracking::Destinations::Snowplow.new
       end
     end
   end

lib/gitlab/tracking/destinations/base.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Tracking
+    module Destinations
+      class Base
+        def event(category, action, label: nil, property: nil, value: nil, context: nil)
+          raise NotImplementedError, "#{self} does not implement #{__method__}"
+        end
+      end
+    end
+  end
+end

lib/gitlab/tracking/destinations/snowplow.rb

+# frozen_string_literal: true
+
+require 'snowplow-tracker'
+
+module Gitlab
+  module Tracking
+    module Destinations
+      class Snowplow < Base
+        extend ::Gitlab::Utils::Override
+
+        override :event
+        def event(category, action, label: nil, property: nil, value: nil, context: nil)
+          return unless enabled?
+
+          tracker.track_struct_event(category, action, label, property, value, context, (Time.now.to_f * 1000).to_i)
+        end
+
+        def self_describing_event(schema_url, event_data_json, context: nil)
+          return unless enabled?
+
+          event_json = SnowplowTracker::SelfDescribingJson.new(schema_url, event_data_json)
+          tracker.track_self_describing_event(event_json, context, (Time.now.to_f * 1000).to_i)
+        end
+
+        private
+
+        def enabled?
+          Gitlab::CurrentSettings.snowplow_enabled?
+        end
+
+        def tracker
+          @tracker ||= SnowplowTracker::Tracker.new(
+            emitter,
+            SnowplowTracker::Subject.new,
+            Gitlab::Tracking::SNOWPLOW_NAMESPACE,
+            Gitlab::CurrentSettings.snowplow_app_id
+          )
+        end
+
+        def emitter
+          SnowplowTracker::AsyncEmitter.new(
+            Gitlab::CurrentSettings.snowplow_collector_hostname,
+            protocol: 'https'
+          )
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/tracking/destinations/snowplow_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Tracking::Destinations::Snowplow do
+  let(:emitter) { SnowplowTracker::Emitter.new('localhost', buffer_size: 1) }
+  let(:tracker) { SnowplowTracker::Tracker.new(emitter, SnowplowTracker::Subject.new, 'namespace', 'app_id') }
+
+  before do
+    stub_application_setting(snowplow_collector_hostname: 'gitfoo.com')
+    stub_application_setting(snowplow_app_id: '_abc123_')
+  end
+
+  around do |example|
+    freeze_time { example.run }
+  end
+
+  context 'when snowplow is enabled' do
+    before do
+      stub_application_setting(snowplow_enabled: true)
+
+      expect(SnowplowTracker::AsyncEmitter)
+        .to receive(:new)
+        .with('gitfoo.com', { protocol: 'https' })
+        .and_return(emitter)
+
+      expect(SnowplowTracker::Tracker)
+        .to receive(:new)
+        .with(emitter, an_instance_of(SnowplowTracker::Subject), Gitlab::Tracking::SNOWPLOW_NAMESPACE, '_abc123_')
+        .and_return(tracker)
+    end
+
+    describe '#event' do
+      it 'sends event to tracker' do
+        allow(tracker).to receive(:track_struct_event).and_call_original
+
+        subject.event('category', 'action', label: 'label', property: 'property', value: 1.5)
+
+        expect(tracker)
+          .to have_received(:track_struct_event)
+          .with('category', 'action', 'label', 'property', 1.5, nil, (Time.now.to_f * 1000).to_i)
+      end
+    end
+
+    describe '#self_describing_event' do
+      it 'sends event to tracker' do
+        allow(tracker).to receive(:track_self_describing_event).and_call_original
+
+        subject.self_describing_event('iglu:com.gitlab/foo/jsonschema/1-0-0', foo: 'bar')
+
+        expect(tracker).to have_received(:track_self_describing_event) do |event, context, timestamp|
+          expect(event.to_json[:schema]).to eq('iglu:com.gitlab/foo/jsonschema/1-0-0')
+          expect(event.to_json[:data]).to eq(foo: 'bar')
+          expect(context).to eq(nil)
+          expect(timestamp).to eq((Time.now.to_f * 1000).to_i)
+        end
+      end
+    end
+  end
+
+  context 'when snowplow is not enabled' do
+    describe '#event' do
+      it 'does not send event to tracker' do
+        expect_any_instance_of(SnowplowTracker::Tracker).not_to receive(:track_struct_event)
+
+        subject.event('category', 'action', label: 'label', property: 'property', value: 1.5)
+      end
+    end
+
+    describe '#self_describing_event' do
+      it 'does not send event to tracker' do
+        expect_any_instance_of(SnowplowTracker::Tracker).not_to receive(:track_self_describing_event)
+
+        subject.self_describing_event('iglu:com.gitlab/foo/jsonschema/1-0-0', foo: 'bar')
+      end
+    end
+  end
+end

spec/lib/gitlab/tracking_spec.rb

@@ -2,13 +2,13 @@
 require 'spec_helper'
 
 RSpec.describe Gitlab::Tracking do
-  let(:timestamp) { Time.utc(2017, 3, 22) }
-
   before do
     stub_application_setting(snowplow_enabled: true)
     stub_application_setting(snowplow_collector_hostname: 'gitfoo.com')
     stub_application_setting(snowplow_cookie_domain: '.gitfoo.com')
     stub_application_setting(snowplow_app_id: '_abc123_')
+
+    described_class.instance_variable_set("@snowplow", nil)
   end
 
   describe '.snowplow_options' do
@@ -35,99 +35,23 @@ RSpec.describe Gitlab::Tracking do
     end
   end
 
-  describe 'tracking events' do
-    shared_examples 'events not tracked' do
-      it 'does not track events' do
-        stub_application_setting(snowplow_enabled: false)
-        expect(SnowplowTracker::AsyncEmitter).not_to receive(:new)
-        expect(SnowplowTracker::Tracker).not_to receive(:new)
-
-        track_event
-      end
-    end
-
-    around do |example|
-      travel_to(timestamp) { example.run }
-    end
-
-    before do
-      described_class.instance_variable_set("@snowplow", nil)
-    end
-
-    let(:tracker) { double }
-
-    def receive_events
-      expect(SnowplowTracker::AsyncEmitter).to receive(:new).with(
-        'gitfoo.com', { protocol: 'https' }
-      ).and_return('_emitter_')
-
-      expect(SnowplowTracker::Tracker).to receive(:new).with(
-        '_emitter_',
-        an_instance_of(SnowplowTracker::Subject),
-        'gl',
-        '_abc123_'
-      ).and_return(tracker)
-    end
-
   describe '.event' do
-      let(:track_event) do
-        described_class.event('category', 'action',
-          label: '_label_',
-          property: '_property_',
-          value: '_value_',
-          context:  nil
-        )
-      end
+    it 'delegates to snowplow destination' do
+      expect_any_instance_of(Gitlab::Tracking::Destinations::Snowplow)
+        .to receive(:event)
+        .with('category', 'action', label: 'label', property: 'property', value: 1.5, context: nil)
 
-      it_behaves_like 'events not tracked'
-
-      it 'can track events' do
-        receive_events
-        expect(tracker).to receive(:track_struct_event).with(
-          'category',
-          'action',
-          '_label_',
-          '_property_',
-          '_value_',
-          nil,
-          (timestamp.to_f * 1000).to_i
-        )
-
-        track_event
+      described_class.event('category', 'action', label: 'label', property: 'property', value: 1.5)
     end
   end
 
   describe '.self_describing_event' do
-      let(:track_event) do
-        described_class.self_describing_event('iglu:com.gitlab/example/jsonschema/1-0-2',
-          {
-            foo: 'bar',
-            foo_count: 42
-          },
-          context: nil
-        )
-      end
-
-      it_behaves_like 'events not tracked'
-
-      it 'can track self describing events' do
-        receive_events
-        expect(SnowplowTracker::SelfDescribingJson).to receive(:new).with(
-          'iglu:com.gitlab/example/jsonschema/1-0-2',
-          {
-            foo: 'bar',
-            foo_count: 42
-          }
-        ).and_return('_event_json_')
+    it 'delegates to snowplow destination' do
+      expect_any_instance_of(Gitlab::Tracking::Destinations::Snowplow)
+        .to receive(:self_describing_event)
+        .with('iglu:com.gitlab/foo/jsonschema/1-0-0', { foo: 'bar' }, context: nil)
 
-        expect(tracker).to receive(:track_self_describing_event).with(
-          '_event_json_',
-          nil,
-          (timestamp.to_f * 1000).to_i
-        )
-
-        track_event
-      end
+      described_class.self_describing_event('iglu:com.gitlab/foo/jsonschema/1-0-0', foo: 'bar')
     end
   end
 end

spec/support/snowplow.rb

@@ -7,7 +7,7 @@ RSpec.configure do |config|
     # WebMock is set up to allow requests to `localhost`
     host = 'localhost'
 
-    allow(Gitlab::Tracking)
+    allow_any_instance_of(Gitlab::Tracking::Destinations::Snowplow)
       .to receive(:emitter)
       .and_return(SnowplowTracker::Emitter.new(host, buffer_size: buffer_size))
 
@@ -17,6 +17,6 @@ RSpec.configure do |config|
   end
 
   config.after(:each, :snowplow) do
-    Gitlab::Tracking.send(:snowplow).flush
+    Gitlab::Tracking.send(:snowplow).send(:tracker).flush
   end
 end