Optionally use new VSA backend on the project level

This change introduces a feature flag (new_project_level_vsa_backend)
where the new backend implementation is going to be used on the project
level value stream analytics page.

app/models/cycle_analytics/level_base.rb

@@ -4,9 +4,52 @@ module CycleAnalytics
   module LevelBase
     STAGES = %i[issue plan code test review staging].freeze
 
+    # This is a temporary adapter class which makes the new value stream (cycle analytics)
+    # backend compatible with the old implementation.
+    class StageAdapter
+      def initialize(stage, options)
+        @stage = stage
+        @options = options
+      end
+
+      # rubocop: disable CodeReuse/Presenter
+      def as_json(serializer: AnalyticsStageSerializer)
+        presenter = Analytics::CycleAnalytics::StagePresenter.new(stage)
+
+        serializer.new.represent(OpenStruct.new(
+                                   title: presenter.title,
+                                   description: presenter.description,
+                                   legend: presenter.legend,
+                                   name: stage.name,
+                                   project_median: median,
+                                   group_median: median
+                                 ))
+      end
+      # rubocop: enable CodeReuse/Presenter
+
+      def events
+        data_collector.records_fetcher.serialized_records
+      end
+
+      def median
+        data_collector.median.seconds
+      end
+
+      alias_method :project_median, :median
+      alias_method :group_median, :median
+
+      private
+
+      attr_reader :stage, :options
+
+      def data_collector
+        @data_collector ||= Gitlab::Analytics::CycleAnalytics::DataCollector.new(stage: stage, params: options)
+      end
+    end
+
     def all_medians_by_stage
       STAGES.each_with_object({}) do |stage_name, medians_per_stage|
-        medians_per_stage[stage_name] = self[stage_name].project_median
+        medians_per_stage[stage_name] = self[stage_name].median
       end
     end
 
@@ -21,7 +64,15 @@ module CycleAnalytics
     end
 
     def [](stage_name)
-      Gitlab::CycleAnalytics::Stage[stage_name].new(options: options)
+      if Feature.enabled?(:new_project_level_vsa_backend, resource_parent)
+        StageAdapter.new(build_stage(stage_name), options)
+      else
+        Gitlab::CycleAnalytics::Stage[stage_name].new(options: options)
+      end
+    end
+
+    def stage_params_by_name(name)
+      Gitlab::Analytics::CycleAnalytics::DefaultStages.find_by_name!(name)
     end
   end
 end

app/models/cycle_analytics/project_level.rb

@@ -20,5 +20,14 @@ module CycleAnalytics
     def permissions(user:)
       Gitlab::CycleAnalytics::Permissions.get(user: user, project: project)
     end
+
+    def build_stage(stage_name)
+      stage_params = stage_params_by_name(stage_name).merge(project: project)
+      Analytics::CycleAnalytics::ProjectStage.new(stage_params)
+    end
+
+    def resource_parent
+      project
+    end
   end
 end

app/views/projects/cycle_analytics/show.html.haml

@@ -49,7 +49,7 @@
                 %span.has-tooltip{ "data-placement" => "top", title: _("The value lying at the midpoint of a series of observed values. E.g., between 3, 5, 9, the median is 5. Between 3, 5, 7, 8, the median is (5+7)/2 = 6."), "aria-hidden" => "true" }
                   = sprite_icon('question-o', css_class: 'gl-text-gray-500')
               %li.event-header.pl-3
-                %span.stage-name.font-weight-bold
+                %span.stage-name.font-weight-bold{ "v-if" => "currentStage && currentStage.legend" }
                   {{ currentStage ? __(currentStage.legend) : __('Related Issues') }}
                 %span.has-tooltip{ "data-placement" => "top", title: _("The collection of events added to the data gathered for that stage."), "aria-hidden" => "true" }
                   = sprite_icon('question-o', css_class: 'gl-text-gray-500')

config/feature_flags/development/new_project_level_vsa_backend.yml

+---
+name: new_project_level_vsa_backend
+introduced_by_url:
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/282435
+milestone: '13.7'
+type: development
+group: group::optimize
+default_enabled: false

ee/app/models/analytics/cycle_analytics/group_level.rb

@@ -37,6 +37,15 @@ module Analytics
           self[stage_name].as_json(serializer: GroupAnalyticsStageSerializer)
         end
       end
+
+      def build_stage(stage_name)
+        stage_params = stage_params_by_name(stage_name).merge(group: group)
+        Analytics::CycleAnalytics::GroupStage.new(stage_params)
+      end
+
+      def resource_parent
+        group
+      end
     end
   end
 end

lib/gitlab/analytics/cycle_analytics/default_stages.rb

@@ -22,6 +22,10 @@ module Gitlab
           ]
         end
 
+        def self.find_by_name!(name)
+          all.find { |raw_stage| raw_stage[:name].to_s.eql?(name.to_s) } || raise("Default stage '#{name}' not found")
+        end
+
         def self.names
           all.map { |stage| stage[:name] }
         end

spec/features/cycle_analytics_spec.rb

@@ -48,6 +48,16 @@ RSpec.describe 'Value Stream Analytics', :js do
         @build = create_cycle(user, project, issue, mr, milestone, pipeline)
         deploy_master(user, project)
 
+        issue.metrics.update!(first_mentioned_in_commit_at: issue.metrics.first_associated_with_milestone_at + 1.day)
+        merge_request = issue.merge_requests_closing_issues.first.merge_request
+        merge_request.update!(created_at: issue.metrics.first_associated_with_milestone_at + 1.day)
+        merge_request.metrics.update!(
+          latest_build_started_at: 4.hours.ago,
+          latest_build_finished_at: 3.hours.ago,
+          merged_at: merge_request.created_at + 1.hour,
+          first_deployed_to_production_at: merge_request.created_at + 2.hours
+        )
+
         sign_in(user)
         visit project_cycle_analytics_path(project)
       end

spec/lib/gitlab/cycle_analytics/events_spec.rb

@@ -40,6 +40,9 @@ RSpec.describe 'value stream analytics events', :aggregate_failures do
 
     before do
       create_commit_referencing_issue(context)
+
+      # Adding extra duration because the new VSA backend filters out 0 durations between these columns
+      context.metrics.update!(first_mentioned_in_commit_at: context.metrics.first_associated_with_milestone_at + 1.day)
     end
 
     it 'has correct attributes' do

spec/models/cycle_analytics/code_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe 'CycleAnalytics#code' do
   let_it_be(:project) { create(:project, :repository) }
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
-  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
 
   subject { project_level }
 

spec/models/cycle_analytics/issue_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe 'CycleAnalytics#issue' do
   let_it_be(:project) { create(:project, :repository) }
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
-  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
 
   subject { project_level }
 

spec/models/cycle_analytics/plan_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe 'CycleAnalytics#plan' do
   let_it_be(:project) { create(:project, :repository) }
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
-  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
 
   subject { project_level }
 

spec/models/cycle_analytics/review_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe 'CycleAnalytics#review' do
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
 
-  subject { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  subject { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
 
   generate_cycle_analytics_spec(
     phase: :review,

spec/models/cycle_analytics/staging_spec.rb

@@ -8,7 +8,7 @@ RSpec.describe 'CycleAnalytics#staging' do
   let_it_be(:project) { create(:project, :repository) }
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
-  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
 
   subject { project_level }
 

spec/models/cycle_analytics/test_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe 'CycleAnalytics#test' do
   let_it_be(:from_date) { 10.days.ago }
   let_it_be(:user) { project.owner }
   let_it_be(:issue) { create(:issue, project: project) }
-  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date }) }
+  let_it_be(:project_level) { CycleAnalytics::ProjectLevel.new(project, options: { from: from_date, current_user: user }) }
   let!(:merge_request) { create_merge_request_closing_issue(user, project, issue) }
 
   subject { project_level }

spec/requests/projects/cycle_analytics_events_spec.rb

@@ -7,108 +7,115 @@ RSpec.describe 'value stream analytics events' do
   let(:project) { create(:project, :repository, public_builds: false) }
   let(:issue) { create(:issue, project: project, created_at: 2.days.ago) }
 
-  describe 'GET /:namespace/:project/value_stream_analytics/events/issues' do
-    before do
-      project.add_developer(user)
+  shared_examples 'value stream analytics events examples' do
+    describe 'GET /:namespace/:project/value_stream_analytics/events/issues' do
+      before do
+        project.add_developer(user)
 
-      3.times do |count|
-        travel_to(Time.now + count.days) do
-          create_cycle
+        3.times do |count|
+          travel_to(Time.now + count.days) do
+            create_cycle
+          end
         end
-      end
-
-      deploy_master(user, project)
-
-      login_as(user)
-    end
-
-    it 'lists the issue events' do
-      get project_cycle_analytics_issue_path(project, format: :json)
 
-      first_issue_iid = project.issues.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
+        deploy_master(user, project)
 
-      expect(json_response['events']).not_to be_empty
-      expect(json_response['events'].first['iid']).to eq(first_issue_iid)
-    end
+        login_as(user)
+      end
 
-    it 'lists the plan events' do
-      get project_cycle_analytics_plan_path(project, format: :json)
+      it 'lists the issue events' do
+        get project_cycle_analytics_issue_path(project, format: :json)
 
-      first_issue_iid = project.issues.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
+        first_issue_iid = project.issues.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
 
-      expect(json_response['events']).not_to be_empty
-      expect(json_response['events'].first['iid']).to eq(first_issue_iid)
-    end
+        expect(json_response['events']).not_to be_empty
+        expect(json_response['events'].first['iid']).to eq(first_issue_iid)
+      end
 
-    it 'lists the code events' do
-      get project_cycle_analytics_code_path(project, format: :json)
+      it 'lists the plan events' do
+        get project_cycle_analytics_plan_path(project, format: :json)
 
-      expect(json_response['events']).not_to be_empty
+        first_issue_iid = project.issues.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
 
-      first_mr_iid = project.merge_requests.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
+        expect(json_response['events']).not_to be_empty
+        expect(json_response['events'].first['iid']).to eq(first_issue_iid)
+      end
 
-      expect(json_response['events'].first['iid']).to eq(first_mr_iid)
-    end
+      it 'lists the code events' do
+        get project_cycle_analytics_code_path(project, format: :json)
 
-    it 'lists the test events', :sidekiq_might_not_need_inline do
-      get project_cycle_analytics_test_path(project, format: :json)
+        expect(json_response['events']).not_to be_empty
 
-      expect(json_response['events']).not_to be_empty
-      expect(json_response['events'].first['date']).not_to be_empty
-    end
+        first_mr_iid = project.merge_requests.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
 
-    it 'lists the review events' do
-      get project_cycle_analytics_review_path(project, format: :json)
+        expect(json_response['events'].first['iid']).to eq(first_mr_iid)
+      end
 
-      first_mr_iid = project.merge_requests.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
+      it 'lists the test events', :sidekiq_inline do
+        get project_cycle_analytics_test_path(project, format: :json)
 
-      expect(json_response['events']).not_to be_empty
-      expect(json_response['events'].first['iid']).to eq(first_mr_iid)
-    end
+        expect(json_response['events']).not_to be_empty
+        expect(json_response['events'].first['date']).not_to be_empty
+      end
 
-    it 'lists the staging events', :sidekiq_might_not_need_inline do
-      get project_cycle_analytics_staging_path(project, format: :json)
+      it 'lists the review events' do
+        get project_cycle_analytics_review_path(project, format: :json)
 
-      expect(json_response['events']).not_to be_empty
-      expect(json_response['events'].first['date']).not_to be_empty
-    end
+        first_mr_iid = project.merge_requests.sort_by_attribute(:created_desc).pluck(:iid).first.to_s
 
-    context 'specific branch' do
-      it 'lists the test events', :sidekiq_might_not_need_inline do
-        branch = project.merge_requests.first.source_branch
+        expect(json_response['events']).not_to be_empty
+        expect(json_response['events'].first['iid']).to eq(first_mr_iid)
+      end
 
-        get project_cycle_analytics_test_path(project, format: :json, branch: branch)
+      it 'lists the staging events', :sidekiq_inline do
+        get project_cycle_analytics_staging_path(project, format: :json)
 
         expect(json_response['events']).not_to be_empty
         expect(json_response['events'].first['date']).not_to be_empty
       end
-    end
 
-    context 'with private project and builds' do
-      before do
-        project.members.last.update(access_level: Gitlab::Access::GUEST)
-      end
+      context 'with private project and builds' do
+        before do
+          project.members.last.update(access_level: Gitlab::Access::GUEST)
+        end
 
-      it 'does not list the test events' do
-        get project_cycle_analytics_test_path(project, format: :json)
+        it 'does not list the test events' do
+          get project_cycle_analytics_test_path(project, format: :json)
 
-        expect(response).to have_gitlab_http_status(:not_found)
-      end
+          expect(response).to have_gitlab_http_status(:not_found)
+        end
 
-      it 'does not list the staging events' do
-        get project_cycle_analytics_staging_path(project, format: :json)
+        it 'does not list the staging events' do
+          get project_cycle_analytics_staging_path(project, format: :json)
 
-        expect(response).to have_gitlab_http_status(:not_found)
-      end
+          expect(response).to have_gitlab_http_status(:not_found)
+        end
 
-      it 'lists the issue events' do
-        get project_cycle_analytics_issue_path(project, format: :json)
+        it 'lists the issue events' do
+          get project_cycle_analytics_issue_path(project, format: :json)
 
-        expect(response).to have_gitlab_http_status(:ok)
+          expect(response).to have_gitlab_http_status(:ok)
+        end
       end
     end
   end
 
+  describe 'when new_project_level_vsa_backend feature flag is off' do
+    before do
+      stub_feature_flags(new_project_level_vsa_backend: false, thing: project)
+    end
+
+    it_behaves_like 'value stream analytics events examples'
+  end
+
+  describe 'when new_project_level_vsa_backend feature flag is on' do
+    before do
+      stub_feature_flags(new_project_level_vsa_backend: true, thing: project)
+    end
+
+    it_behaves_like 'value stream analytics events examples'
+  end
+
   def create_cycle
     milestone = create(:milestone, project: project)
     issue.update(milestone: milestone)
@@ -123,5 +130,7 @@ RSpec.describe 'value stream analytics events' do
     merge_merge_requests_closing_issue(user, project, issue)
 
     ProcessCommitWorker.new.perform(project.id, user.id, mr.commits.last.to_hash)
+
+    mr.metrics.update!(latest_build_started_at: 1.hour.ago, latest_build_finished_at: Time.now)
   end
 end