Extract experimentation concern

There is no need to have this in one class and it's easier to follow
when split up.

lib/gitlab/experimentation.rb

 # frozen_string_literal: true
 
-require 'zlib'
-
 # == Experimentation
 #
 # Utility module for A/B testing experimental features. Define your experiments in the `EXPERIMENTS` constant.
@@ -91,126 +89,6 @@ module Gitlab
       }
     }.freeze
 
-    # Controller concern that checks if an `experimentation_subject_id cookie` is present and sets it if absent.
-    # Used for A/B testing of experimental features. Exposes the `experiment_enabled?(experiment_name)` method
-    # to controllers and views. It returns true when the experiment is enabled and the user is selected as part
-    # of the experimental group.
-    #
-    module ControllerConcern
-      include ::Gitlab::Experimentation::GroupTypes
-      extend ActiveSupport::Concern
-
-      included do
-        before_action :set_experimentation_subject_id_cookie, unless: :dnt_enabled?
-        helper_method :experiment_enabled?, :experiment_tracking_category_and_group
-      end
-
-      def set_experimentation_subject_id_cookie
-        return if cookies[:experimentation_subject_id].present?
-
-        cookies.permanent.signed[:experimentation_subject_id] = {
-          value: SecureRandom.uuid,
-          secure: ::Gitlab.config.gitlab.https,
-          httponly: true
-        }
-      end
-
-      def push_frontend_experiment(experiment_key)
-        var_name = experiment_key.to_s.camelize(:lower)
-        enabled = experiment_enabled?(experiment_key)
-
-        gon.push({ experiments: { var_name => enabled } }, true)
-      end
-
-      def experiment_enabled?(experiment_key)
-        return false if dnt_enabled?
-
-        return true if Experimentation.enabled_for_value?(experiment_key, experimentation_subject_index(experiment_key))
-        return true if forced_enabled?(experiment_key)
-
-        false
-      end
-
-      def track_experiment_event(experiment_key, action, value = nil)
-        return if dnt_enabled?
-
-        track_experiment_event_for(experiment_key, action, value) do |tracking_data|
-          ::Gitlab::Tracking.event(tracking_data.delete(:category), tracking_data.delete(:action), **tracking_data)
-        end
-      end
-
-      def frontend_experimentation_tracking_data(experiment_key, action, value = nil)
-        return if dnt_enabled?
-
-        track_experiment_event_for(experiment_key, action, value) do |tracking_data|
-          gon.push(tracking_data: tracking_data)
-        end
-      end
-
-      def record_experiment_user(experiment_key)
-        return if dnt_enabled?
-        return unless Experimentation.enabled?(experiment_key) && current_user
-
-        ::Experiment.add_user(experiment_key, tracking_group(experiment_key), current_user)
-      end
-
-      def experiment_tracking_category_and_group(experiment_key)
-        "#{tracking_category(experiment_key)}:#{tracking_group(experiment_key, '_group')}"
-      end
-
-      private
-
-      def dnt_enabled?
-        Gitlab::Utils.to_boolean(request.headers['DNT'])
-      end
-
-      def experimentation_subject_id
-        cookies.signed[:experimentation_subject_id]
-      end
-
-      def experimentation_subject_index(experiment_key)
-        return if experimentation_subject_id.blank?
-
-        if Experimentation.experiment(experiment_key).use_backwards_compatible_subject_index
-          experimentation_subject_id.delete('-').hex % 100
-        else
-          Zlib.crc32("#{experiment_key}#{experimentation_subject_id}") % 100
-        end
-      end
-
-      def track_experiment_event_for(experiment_key, action, value)
-        return unless Experimentation.enabled?(experiment_key)
-
-        yield experimentation_tracking_data(experiment_key, action, value)
-      end
-
-      def experimentation_tracking_data(experiment_key, action, value)
-        {
-          category: tracking_category(experiment_key),
-          action: action,
-          property: tracking_group(experiment_key, "_group"),
-          label: experimentation_subject_id,
-          value: value
-        }.compact
-      end
-
-      def tracking_category(experiment_key)
-        Experimentation.experiment(experiment_key).tracking_category
-      end
-
-      def tracking_group(experiment_key, suffix = nil)
-        return unless Experimentation.enabled?(experiment_key)
-
-        group = experiment_enabled?(experiment_key) ? GROUP_EXPERIMENTAL : GROUP_CONTROL
-
-        suffix ? "#{group}#{suffix}" : group
-      end
-
-      def forced_enabled?(experiment_key)
-        params.has_key?(:force_experiment) && params[:force_experiment] == experiment_key.to_s
-      end
-    end
-
     class << self
       def experiment(key)
         Experiment.new(EXPERIMENTS[key].merge(key: key))

lib/gitlab/experimentation/controller_concern.rb

+# frozen_string_literal: true
+
+require 'zlib'
+
+# Controller concern that checks if an `experimentation_subject_id cookie` is present and sets it if absent.
+# Used for A/B testing of experimental features. Exposes the `experiment_enabled?(experiment_name)` method
+# to controllers and views. It returns true when the experiment is enabled and the user is selected as part
+# of the experimental group.
+#
+module Gitlab
+  module Experimentation
+    module ControllerConcern
+      include ::Gitlab::Experimentation::GroupTypes
+      extend ActiveSupport::Concern
+
+      included do
+        before_action :set_experimentation_subject_id_cookie, unless: :dnt_enabled?
+        helper_method :experiment_enabled?, :experiment_tracking_category_and_group
+      end
+
+      def set_experimentation_subject_id_cookie
+        return if cookies[:experimentation_subject_id].present?
+
+        cookies.permanent.signed[:experimentation_subject_id] = {
+          value: SecureRandom.uuid,
+          secure: ::Gitlab.config.gitlab.https,
+          httponly: true
+        }
+      end
+
+      def push_frontend_experiment(experiment_key)
+        var_name = experiment_key.to_s.camelize(:lower)
+        enabled = experiment_enabled?(experiment_key)
+
+        gon.push({ experiments: { var_name => enabled } }, true)
+      end
+
+      def experiment_enabled?(experiment_key)
+        return false if dnt_enabled?
+
+        return true if Experimentation.enabled_for_value?(experiment_key, experimentation_subject_index(experiment_key))
+        return true if forced_enabled?(experiment_key)
+
+        false
+      end
+
+      def track_experiment_event(experiment_key, action, value = nil)
+        return if dnt_enabled?
+
+        track_experiment_event_for(experiment_key, action, value) do |tracking_data|
+          ::Gitlab::Tracking.event(tracking_data.delete(:category), tracking_data.delete(:action), **tracking_data)
+        end
+      end
+
+      def frontend_experimentation_tracking_data(experiment_key, action, value = nil)
+        return if dnt_enabled?
+
+        track_experiment_event_for(experiment_key, action, value) do |tracking_data|
+          gon.push(tracking_data: tracking_data)
+        end
+      end
+
+      def record_experiment_user(experiment_key)
+        return if dnt_enabled?
+        return unless Experimentation.enabled?(experiment_key) && current_user
+
+        ::Experiment.add_user(experiment_key, tracking_group(experiment_key), current_user)
+      end
+
+      def experiment_tracking_category_and_group(experiment_key)
+        "#{tracking_category(experiment_key)}:#{tracking_group(experiment_key, '_group')}"
+      end
+
+      private
+
+      def dnt_enabled?
+        Gitlab::Utils.to_boolean(request.headers['DNT'])
+      end
+
+      def experimentation_subject_id
+        cookies.signed[:experimentation_subject_id]
+      end
+
+      def experimentation_subject_index(experiment_key)
+        return if experimentation_subject_id.blank?
+
+        if Experimentation.experiment(experiment_key).use_backwards_compatible_subject_index
+          experimentation_subject_id.delete('-').hex % 100
+        else
+          Zlib.crc32("#{experiment_key}#{experimentation_subject_id}") % 100
+        end
+      end
+
+      def track_experiment_event_for(experiment_key, action, value)
+        return unless Experimentation.enabled?(experiment_key)
+
+        yield experimentation_tracking_data(experiment_key, action, value)
+      end
+
+      def experimentation_tracking_data(experiment_key, action, value)
+        {
+          category: tracking_category(experiment_key),
+          action: action,
+          property: tracking_group(experiment_key, "_group"),
+          label: experimentation_subject_id,
+          value: value
+        }.compact
+      end
+
+      def tracking_category(experiment_key)
+        Experimentation.experiment(experiment_key).tracking_category
+      end
+
+      def tracking_group(experiment_key, suffix = nil)
+        return unless Experimentation.enabled?(experiment_key)
+
+        group = experiment_enabled?(experiment_key) ? GROUP_EXPERIMENTAL : GROUP_CONTROL
+
+        suffix ? "#{group}#{suffix}" : group
+      end
+
+      def forced_enabled?(experiment_key)
+        params.has_key?(:force_experiment) && params[:force_experiment] == experiment_key.to_s
+      end
+    end
+  end
+end

spec/lib/gitlab/experimentation/controller_concern_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Experimentation::ControllerConcern, type: :controller do
+  before do
+    stub_const('Gitlab::Experimentation::EXPERIMENTS', {
+        backwards_compatible_test_experiment: {
+          environment: environment,
+          tracking_category: 'Team',
+          use_backwards_compatible_subject_index: true
+        },
+        test_experiment: {
+          environment: environment,
+          tracking_category: 'Team'
+        }
+      }
+    )
+
+    Feature.enable_percentage_of_time(:backwards_compatible_test_experiment_experiment_percentage, enabled_percentage)
+    Feature.enable_percentage_of_time(:test_experiment_experiment_percentage, enabled_percentage)
+  end
+
+  let(:environment) { Rails.env.test? }
+  let(:enabled_percentage) { 10 }
+
+  controller(ApplicationController) do
+    include Gitlab::Experimentation::ControllerConcern
+
+    def index
+      head :ok
+    end
+  end
+
+  describe '#set_experimentation_subject_id_cookie' do
+    let(:do_not_track) { nil }
+    let(:cookie) { cookies.permanent.signed[:experimentation_subject_id] }
+
+    before do
+      request.headers['DNT'] = do_not_track if do_not_track.present?
+
+      get :index
+    end
+
+    context 'cookie is present' do
+      before do
+        cookies[:experimentation_subject_id] = 'test'
+      end
+
+      it 'does not change the cookie' do
+        expect(cookies[:experimentation_subject_id]).to eq 'test'
+      end
+    end
+
+    context 'cookie is not present' do
+      it 'sets a permanent signed cookie' do
+        expect(cookie).to be_present
+      end
+
+      context 'DNT: 0' do
+        let(:do_not_track) { '0' }
+
+        it 'sets a permanent signed cookie' do
+          expect(cookie).to be_present
+        end
+      end
+
+      context 'DNT: 1' do
+        let(:do_not_track) { '1' }
+
+        it 'does nothing' do
+          expect(cookie).not_to be_present
+        end
+      end
+    end
+  end
+
+  describe '#push_frontend_experiment' do
+    it 'pushes an experiment to the frontend' do
+      gon = instance_double('gon')
+      experiments = { experiments: { 'myExperiment' => true } }
+
+      stub_experiment_for_user(my_experiment: true)
+      allow(controller).to receive(:gon).and_return(gon)
+
+      expect(gon).to receive(:push).with(experiments, true)
+
+      controller.push_frontend_experiment(:my_experiment)
+    end
+  end
+
+  describe '#experiment_enabled?' do
+    def check_experiment(exp_key = :test_experiment)
+      controller.experiment_enabled?(exp_key)
+    end
+
+    subject { check_experiment }
+
+    context 'cookie is not present' do
+      it 'calls Gitlab::Experimentation.enabled_for_value? with the name of the experiment and an experimentation_subject_index of nil' do
+        expect(Gitlab::Experimentation).to receive(:enabled_for_value?).with(:test_experiment, nil)
+        check_experiment
+      end
+    end
+
+    context 'cookie is present' do
+      using RSpec::Parameterized::TableSyntax
+
+      before do
+        cookies.permanent.signed[:experimentation_subject_id] = 'abcd-1234'
+        get :index
+      end
+
+      where(:experiment_key, :index_value) do
+        :test_experiment | 40 # Zlib.crc32('test_experimentabcd-1234') % 100 = 40
+        :backwards_compatible_test_experiment | 76 # 'abcd1234'.hex % 100 = 76
+      end
+
+      with_them do
+        it 'calls Gitlab::Experimentation.enabled_for_value? with the name of the experiment and the calculated experimentation_subject_index based on the uuid' do
+          expect(Gitlab::Experimentation).to receive(:enabled_for_value?).with(experiment_key, index_value)
+          check_experiment(experiment_key)
+        end
+      end
+    end
+
+    it 'returns true when DNT: 0 is set in the request' do
+      allow(Gitlab::Experimentation).to receive(:enabled_for_value?) { true }
+      controller.request.headers['DNT'] = '0'
+
+      is_expected.to be_truthy
+    end
+
+    it 'returns false when DNT: 1 is set in the request' do
+      allow(Gitlab::Experimentation).to receive(:enabled_for_value?) { true }
+      controller.request.headers['DNT'] = '1'
+
+      is_expected.to be_falsy
+    end
+
+    describe 'URL parameter to force enable experiment' do
+      it 'returns true unconditionally' do
+        get :index, params: { force_experiment: :test_experiment }
+
+        is_expected.to be_truthy
+      end
+    end
+  end
+
+  describe '#track_experiment_event', :snowplow do
+    context 'when the experiment is enabled' do
+      before do
+        stub_experiment(test_experiment: true)
+      end
+
+      context 'the user is part of the experimental group' do
+        before do
+          stub_experiment_for_user(test_experiment: true)
+        end
+
+        it 'tracks the event with the right parameters' do
+          controller.track_experiment_event(:test_experiment, 'start', 1)
+
+          expect_snowplow_event(
+            category: 'Team',
+            action: 'start',
+            property: 'experimental_group',
+            value: 1
+          )
+        end
+      end
+
+      context 'the user is part of the control group' do
+        before do
+          stub_experiment_for_user(test_experiment: false)
+        end
+
+        it 'tracks the event with the right parameters' do
+          controller.track_experiment_event(:test_experiment, 'start', 1)
+
+          expect_snowplow_event(
+            category: 'Team',
+            action: 'start',
+            property: 'control_group',
+            value: 1
+          )
+        end
+      end
+
+      context 'do not track is disabled' do
+        before do
+          request.headers['DNT'] = '0'
+        end
+
+        it 'does track the event' do
+          controller.track_experiment_event(:test_experiment, 'start', 1)
+
+          expect_snowplow_event(
+            category: 'Team',
+            action: 'start',
+            property: 'control_group',
+            value: 1
+          )
+        end
+      end
+
+      context 'do not track enabled' do
+        before do
+          request.headers['DNT'] = '1'
+        end
+
+        it 'does not track the event' do
+          controller.track_experiment_event(:test_experiment, 'start', 1)
+
+          expect_no_snowplow_event
+        end
+      end
+    end
+
+    context 'when the experiment is disabled' do
+      before do
+        stub_experiment(test_experiment: false)
+      end
+
+      it 'does not track the event' do
+        controller.track_experiment_event(:test_experiment, 'start')
+
+        expect_no_snowplow_event
+      end
+    end
+  end
+
+  describe '#frontend_experimentation_tracking_data' do
+    context 'when the experiment is enabled' do
+      before do
+        stub_experiment(test_experiment: true)
+      end
+
+      context 'the user is part of the experimental group' do
+        before do
+          stub_experiment_for_user(test_experiment: true)
+        end
+
+        it 'pushes the right parameters to gon' do
+          controller.frontend_experimentation_tracking_data(:test_experiment, 'start', 'team_id')
+          expect(Gon.tracking_data).to eq(
+            {
+              category: 'Team',
+              action: 'start',
+              property: 'experimental_group',
+              value: 'team_id'
+            }
+          )
+        end
+      end
+
+      context 'the user is part of the control group' do
+        before do
+          allow_next_instance_of(described_class) do |instance|
+            allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
+          end
+        end
+
+        it 'pushes the right parameters to gon' do
+          controller.frontend_experimentation_tracking_data(:test_experiment, 'start', 'team_id')
+          expect(Gon.tracking_data).to eq(
+            {
+              category: 'Team',
+              action: 'start',
+              property: 'control_group',
+              value: 'team_id'
+            }
+          )
+        end
+
+        it 'does not send nil value to gon' do
+          controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
+          expect(Gon.tracking_data).to eq(
+            {
+              category: 'Team',
+              action: 'start',
+              property: 'control_group'
+            }
+          )
+        end
+      end
+
+      context 'do not track disabled' do
+        before do
+          request.headers['DNT'] = '0'
+        end
+
+        it 'pushes the right parameters to gon' do
+          controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
+
+          expect(Gon.tracking_data).to eq(
+            {
+              category: 'Team',
+              action: 'start',
+              property: 'control_group'
+            }
+          )
+        end
+      end
+
+      context 'do not track enabled' do
+        before do
+          request.headers['DNT'] = '1'
+        end
+
+        it 'does not push data to gon' do
+          controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
+
+          expect(Gon.method_defined?(:tracking_data)).to be_falsey
+        end
+      end
+    end
+
+    context 'when the experiment is disabled' do
+      before do
+        stub_experiment(test_experiment: false)
+      end
+
+      it 'does not push data to gon' do
+        expect(Gon.method_defined?(:tracking_data)).to be_falsey
+        controller.track_experiment_event(:test_experiment, 'start')
+      end
+    end
+  end
+
+  describe '#record_experiment_user' do
+    let(:user) { build(:user) }
+
+    context 'when the experiment is enabled' do
+      before do
+        stub_experiment(test_experiment: true)
+        allow(controller).to receive(:current_user).and_return(user)
+      end
+
+      context 'the user is part of the experimental group' do
+        before do
+          stub_experiment_for_user(test_experiment: true)
+        end
+
+        it 'calls add_user on the Experiment model' do
+          expect(::Experiment).to receive(:add_user).with(:test_experiment, :experimental, user)
+
+          controller.record_experiment_user(:test_experiment)
+        end
+      end
+
+      context 'the user is part of the control group' do
+        before do
+          allow_next_instance_of(described_class) do |instance|
+            allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
+          end
+        end
+
+        it 'calls add_user on the Experiment model' do
+          expect(::Experiment).to receive(:add_user).with(:test_experiment, :control, user)
+
+          controller.record_experiment_user(:test_experiment)
+        end
+      end
+    end
+
+    context 'when the experiment is disabled' do
+      before do
+        stub_experiment(test_experiment: false)
+        allow(controller).to receive(:current_user).and_return(user)
+      end
+
+      it 'does not call add_user on the Experiment model' do
+        expect(::Experiment).not_to receive(:add_user)
+
+        controller.record_experiment_user(:test_experiment)
+      end
+    end
+
+    context 'when there is no current_user' do
+      before do
+        stub_experiment(test_experiment: true)
+      end
+
+      it 'does not call add_user on the Experiment model' do
+        expect(::Experiment).not_to receive(:add_user)
+
+        controller.record_experiment_user(:test_experiment)
+      end
+    end
+
+    context 'do not track' do
+      before do
+        allow(controller).to receive(:current_user).and_return(user)
+        allow_next_instance_of(described_class) do |instance|
+          allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
+        end
+      end
+
+      context 'is disabled' do
+        before do
+          request.headers['DNT'] = '0'
+        end
+
+        it 'calls add_user on the Experiment model' do
+          expect(::Experiment).to receive(:add_user).with(:test_experiment, :control, user)
+
+          controller.record_experiment_user(:test_experiment)
+        end
+      end
+
+      context 'is enabled' do
+        before do
+          request.headers['DNT'] = '1'
+        end
+
+        it 'does not call add_user on the Experiment model' do
+          expect(::Experiment).not_to receive(:add_user)
+
+          controller.record_experiment_user(:test_experiment)
+        end
+      end
+    end
+  end
+
+  describe '#experiment_tracking_category_and_group' do
+    let_it_be(:experiment_key) { :test_something }
+
+    subject { controller.experiment_tracking_category_and_group(experiment_key) }
+
+    it 'returns a string with the experiment tracking category & group joined with a ":"' do
+      expect(controller).to receive(:tracking_category).with(experiment_key).and_return('Experiment::Category')
+      expect(controller).to receive(:tracking_group).with(experiment_key, '_group').and_return('experimental_group')
+
+      expect(subject).to eq('Experiment::Category:experimental_group')
+    end
+  end
+end

spec/lib/gitlab/experimentation_spec.rb

@@ -51,420 +51,6 @@ RSpec.describe Gitlab::Experimentation, :snowplow do
   let(:environment) { Rails.env.test? }
   let(:enabled_percentage) { 10 }
 
-  describe Gitlab::Experimentation::ControllerConcern, type: :controller do
-    controller(ApplicationController) do
-      include Gitlab::Experimentation::ControllerConcern
-
-      def index
-        head :ok
-      end
-    end
-
-    describe '#set_experimentation_subject_id_cookie' do
-      let(:do_not_track) { nil }
-      let(:cookie) { cookies.permanent.signed[:experimentation_subject_id] }
-
-      before do
-        request.headers['DNT'] = do_not_track if do_not_track.present?
-
-        get :index
-      end
-
-      context 'cookie is present' do
-        before do
-          cookies[:experimentation_subject_id] = 'test'
-        end
-
-        it 'does not change the cookie' do
-          expect(cookies[:experimentation_subject_id]).to eq 'test'
-        end
-      end
-
-      context 'cookie is not present' do
-        it 'sets a permanent signed cookie' do
-          expect(cookie).to be_present
-        end
-
-        context 'DNT: 0' do
-          let(:do_not_Track) { '0' }
-
-          it 'sets a permanent signed cookie' do
-            expect(cookie).to be_present
-          end
-        end
-
-        context 'DNT: 1' do
-          let(:do_not_track) { '1' }
-
-          it 'does nothing' do
-            expect(cookie).not_to be_present
-          end
-        end
-      end
-    end
-
-    describe '#push_frontend_experiment' do
-      it 'pushes an experiment to the frontend' do
-        gon = instance_double('gon')
-        experiments = { experiments: { 'myExperiment' => true } }
-
-        stub_experiment_for_user(my_experiment: true)
-        allow(controller).to receive(:gon).and_return(gon)
-
-        expect(gon).to receive(:push).with(experiments, true)
-
-        controller.push_frontend_experiment(:my_experiment)
-      end
-    end
-
-    describe '#experiment_enabled?' do
-      def check_experiment(exp_key = :test_experiment)
-        controller.experiment_enabled?(exp_key)
-      end
-
-      subject { check_experiment }
-
-      context 'cookie is not present' do
-        it 'calls Gitlab::Experimentation.enabled_for_value? with the name of the experiment and an experimentation_subject_index of nil' do
-          expect(Gitlab::Experimentation).to receive(:enabled_for_value?).with(:test_experiment, nil)
-          check_experiment
-        end
-      end
-
-      context 'cookie is present' do
-        using RSpec::Parameterized::TableSyntax
-
-        before do
-          cookies.permanent.signed[:experimentation_subject_id] = 'abcd-1234'
-          get :index
-        end
-
-        where(:experiment_key, :index_value) do
-          :test_experiment | 40 # Zlib.crc32('test_experimentabcd-1234') % 100 = 40
-          :backwards_compatible_test_experiment | 76 # 'abcd1234'.hex % 100 = 76
-        end
-
-        with_them do
-          it 'calls Gitlab::Experimentation.enabled_for_value? with the name of the experiment and the calculated experimentation_subject_index based on the uuid' do
-            expect(Gitlab::Experimentation).to receive(:enabled_for_value?).with(experiment_key, index_value)
-            check_experiment(experiment_key)
-          end
-        end
-      end
-
-      it 'returns true when DNT: 0 is set in the request' do
-        allow(Gitlab::Experimentation).to receive(:enabled_for_value?) { true }
-        controller.request.headers['DNT'] = '0'
-
-        is_expected.to be_truthy
-      end
-
-      it 'returns false when DNT: 1 is set in the request' do
-        allow(Gitlab::Experimentation).to receive(:enabled_for_value?) { true }
-        controller.request.headers['DNT'] = '1'
-
-        is_expected.to be_falsy
-      end
-
-      describe 'URL parameter to force enable experiment' do
-        it 'returns true unconditionally' do
-          get :index, params: { force_experiment: :test_experiment }
-
-          is_expected.to be_truthy
-        end
-      end
-    end
-
-    describe '#track_experiment_event' do
-      context 'when the experiment is enabled' do
-        before do
-          stub_experiment(test_experiment: true)
-        end
-
-        context 'the user is part of the experimental group' do
-          before do
-            stub_experiment_for_user(test_experiment: true)
-          end
-
-          it 'tracks the event with the right parameters' do
-            controller.track_experiment_event(:test_experiment, 'start', 1)
-
-            expect_snowplow_event(
-              category: 'Team',
-              action: 'start',
-              property: 'experimental_group',
-              value: 1
-            )
-          end
-        end
-
-        context 'the user is part of the control group' do
-          before do
-            stub_experiment_for_user(test_experiment: false)
-          end
-
-          it 'tracks the event with the right parameters' do
-            controller.track_experiment_event(:test_experiment, 'start', 1)
-
-            expect_snowplow_event(
-              category: 'Team',
-              action: 'start',
-              property: 'control_group',
-              value: 1
-            )
-          end
-        end
-
-        context 'do not track is disabled' do
-          before do
-            request.headers['DNT'] = '0'
-          end
-
-          it 'does track the event' do
-            controller.track_experiment_event(:test_experiment, 'start', 1)
-
-            expect_snowplow_event(
-              category: 'Team',
-              action: 'start',
-              property: 'control_group',
-              value: 1
-            )
-          end
-        end
-
-        context 'do not track enabled' do
-          before do
-            request.headers['DNT'] = '1'
-          end
-
-          it 'does not track the event' do
-            controller.track_experiment_event(:test_experiment, 'start', 1)
-
-            expect_no_snowplow_event
-          end
-        end
-      end
-
-      context 'when the experiment is disabled' do
-        before do
-          stub_experiment(test_experiment: false)
-        end
-
-        it 'does not track the event' do
-          controller.track_experiment_event(:test_experiment, 'start')
-
-          expect_no_snowplow_event
-        end
-      end
-    end
-
-    describe '#frontend_experimentation_tracking_data' do
-      context 'when the experiment is enabled' do
-        before do
-          stub_experiment(test_experiment: true)
-        end
-
-        context 'the user is part of the experimental group' do
-          before do
-            stub_experiment_for_user(test_experiment: true)
-          end
-
-          it 'pushes the right parameters to gon' do
-            controller.frontend_experimentation_tracking_data(:test_experiment, 'start', 'team_id')
-            expect(Gon.tracking_data).to eq(
-              {
-                category: 'Team',
-                action: 'start',
-                property: 'experimental_group',
-                value: 'team_id'
-              }
-            )
-          end
-        end
-
-        context 'the user is part of the control group' do
-          before do
-            allow_next_instance_of(described_class) do |instance|
-              allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
-            end
-          end
-
-          it 'pushes the right parameters to gon' do
-            controller.frontend_experimentation_tracking_data(:test_experiment, 'start', 'team_id')
-            expect(Gon.tracking_data).to eq(
-              {
-                category: 'Team',
-                action: 'start',
-                property: 'control_group',
-                value: 'team_id'
-              }
-            )
-          end
-
-          it 'does not send nil value to gon' do
-            controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
-            expect(Gon.tracking_data).to eq(
-              {
-                category: 'Team',
-                action: 'start',
-                property: 'control_group'
-              }
-            )
-          end
-        end
-
-        context 'do not track disabled' do
-          before do
-            request.headers['DNT'] = '0'
-          end
-
-          it 'pushes the right parameters to gon' do
-            controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
-
-            expect(Gon.tracking_data).to eq(
-              {
-                category: 'Team',
-                action: 'start',
-                property: 'control_group'
-              }
-            )
-          end
-        end
-
-        context 'do not track enabled' do
-          before do
-            request.headers['DNT'] = '1'
-          end
-
-          it 'does not push data to gon' do
-            controller.frontend_experimentation_tracking_data(:test_experiment, 'start')
-
-            expect(Gon.method_defined?(:tracking_data)).to be_falsey
-          end
-        end
-      end
-
-      context 'when the experiment is disabled' do
-        before do
-          stub_experiment(test_experiment: false)
-        end
-
-        it 'does not push data to gon' do
-          expect(Gon.method_defined?(:tracking_data)).to be_falsey
-          controller.track_experiment_event(:test_experiment, 'start')
-        end
-      end
-    end
-
-    describe '#record_experiment_user' do
-      let(:user) { build(:user) }
-
-      context 'when the experiment is enabled' do
-        before do
-          stub_experiment(test_experiment: true)
-          allow(controller).to receive(:current_user).and_return(user)
-        end
-
-        context 'the user is part of the experimental group' do
-          before do
-            stub_experiment_for_user(test_experiment: true)
-          end
-
-          it 'calls add_user on the Experiment model' do
-            expect(::Experiment).to receive(:add_user).with(:test_experiment, :experimental, user)
-
-            controller.record_experiment_user(:test_experiment)
-          end
-        end
-
-        context 'the user is part of the control group' do
-          before do
-            allow_next_instance_of(described_class) do |instance|
-              allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
-            end
-          end
-
-          it 'calls add_user on the Experiment model' do
-            expect(::Experiment).to receive(:add_user).with(:test_experiment, :control, user)
-
-            controller.record_experiment_user(:test_experiment)
-          end
-        end
-      end
-
-      context 'when the experiment is disabled' do
-        before do
-          stub_experiment(test_experiment: false)
-          allow(controller).to receive(:current_user).and_return(user)
-        end
-
-        it 'does not call add_user on the Experiment model' do
-          expect(::Experiment).not_to receive(:add_user)
-
-          controller.record_experiment_user(:test_experiment)
-        end
-      end
-
-      context 'when there is no current_user' do
-        before do
-          stub_experiment(test_experiment: true)
-        end
-
-        it 'does not call add_user on the Experiment model' do
-          expect(::Experiment).not_to receive(:add_user)
-
-          controller.record_experiment_user(:test_experiment)
-        end
-      end
-
-      context 'do not track' do
-        before do
-          allow(controller).to receive(:current_user).and_return(user)
-          allow_next_instance_of(described_class) do |instance|
-            allow(instance).to receive(:experiment_enabled?).with(:test_experiment).and_return(false)
-          end
-        end
-
-        context 'is disabled' do
-          before do
-            request.headers['DNT'] = '0'
-          end
-
-          it 'calls add_user on the Experiment model' do
-            expect(::Experiment).to receive(:add_user).with(:test_experiment, :control, user)
-
-            controller.record_experiment_user(:test_experiment)
-          end
-        end
-
-        context 'is enabled' do
-          before do
-            request.headers['DNT'] = '1'
-          end
-
-          it 'does not call add_user on the Experiment model' do
-            expect(::Experiment).not_to receive(:add_user)
-
-            controller.record_experiment_user(:test_experiment)
-          end
-        end
-      end
-    end
-
-    describe '#experiment_tracking_category_and_group' do
-      let_it_be(:experiment_key) { :test_something }
-
-      subject { controller.experiment_tracking_category_and_group(experiment_key) }
-
-      it 'returns a string with the experiment tracking category & group joined with a ":"' do
-        expect(controller).to receive(:tracking_category).with(experiment_key).and_return('Experiment::Category')
-        expect(controller).to receive(:tracking_group).with(experiment_key, '_group').and_return('experimental_group')
-
-        expect(subject).to eq('Experiment::Category:experimental_group')
-      end
-    end
-  end
-
   describe '.enabled?' do
     subject { described_class.enabled?(:test_experiment) }