Allow left-join stage events

This change adds the capability to left-join stage event timestamp
columns.

ee/lib/gitlab/analytics/cycle_analytics/stage_events/label_based_stage_event.rb

@@ -42,6 +42,14 @@ module Gitlab
           end
           # rubocop: enable CodeReuse/ActiveRecord
 
+          # rubocop: disable CodeReuse/ActiveRecord
+          def include_in(query)
+            query
+              .from(Arel::Nodes::Grouping.new(Arel.sql(object_type.all.to_sql)).as(object_type.table_name))
+              .joins("LEFT JOIN LATERAL (#{subquery.to_sql}) #{join_expression_name} ON TRUE")
+          end
+          # rubocop: enable CodeReuse/ActiveRecord
+
           private
 
           def resource_label_events_table

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_closed_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueClosed do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue, closed_at: Time.current) }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_first_added_to_board_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueFirstAddedToBoard do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue).tap { |i| i.metrics.update!(first_added_to_board_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_first_associated_with_milestone_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueFirstAssociatedWithMilestone do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue).tap { |i| i.metrics.update!(first_associated_with_milestone_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_label_added_spec.rb

@@ -8,4 +8,21 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueLabelAdded d
     let(:params) { { label: GroupLabel.new(id: label_id) } }
     let(:expected_hash_code) { Digest::SHA256.hexdigest("#{instance.class.identifier}-#{label_id}") }
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:project) { create(:project) }
+    let_it_be(:record_with_data) { create(:issue, project: project) }
+    let_it_be(:record_without_data) { create(:issue) }
+    let_it_be(:label) { create(:label, project: project) }
+    let_it_be(:user) { project.owner }
+
+    let(:params) { { label: label } }
+
+    before(:context) do
+      # adding label via the service so the resource_label_events record is populated
+      Sidekiq::Worker.skipping_transaction_check do
+        Issues::UpdateService.new(project: project, current_user: user, params: { label_ids: [label.id] }).execute(record_with_data)
+      end
+    end
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_label_removed_spec.rb

@@ -8,4 +8,20 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueLabelRemoved
     let(:params) { { label: GroupLabel.new(id: label_id) } }
     let(:expected_hash_code) { Digest::SHA256.hexdigest("#{instance.class.identifier}-#{label_id}") }
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:project) { create(:project) }
+    let_it_be(:label) { create(:label, project: project) }
+    let_it_be(:record_with_data) { create(:labeled_issue, project: project, labels: [label]) }
+    let_it_be(:record_without_data) { create(:issue) }
+    let_it_be(:user) { project.owner }
+
+    let(:params) { { label: label } }
+
+    before(:context) do
+      Sidekiq::Worker.skipping_transaction_check do
+        Issues::UpdateService.new(project: project, current_user: user, params: { label_ids: [] }).execute(record_with_data)
+      end
+    end
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_closed_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestClosed do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(latest_closed_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_first_commit_at_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestFirstCommitAt do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(first_commit_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_label_added_spec.rb

@@ -8,4 +8,20 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestLabel
     let(:params) { { label: GroupLabel.new(id: label_id) } }
     let(:expected_hash_code) { Digest::SHA256.hexdigest("#{instance.class.identifier}-#{label_id}") }
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:project) { create(:project, :repository) }
+    let_it_be(:record_with_data) { create(:merge_request, :unique_branches, source_project: project) }
+    let_it_be(:record_without_data) { create(:merge_request) }
+    let_it_be(:label) { create(:label, project: project) }
+    let_it_be(:user) { project.owner }
+
+    let(:params) { { label: label } }
+
+    before(:context) do
+      Sidekiq::Worker.skipping_transaction_check do
+        MergeRequests::UpdateService.new(project: project, current_user: user, params: { label_ids: [label.id] }).execute(record_with_data)
+      end
+    end
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_label_removed_spec.rb

@@ -8,4 +8,20 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestLabel
     let(:params) { { label: GroupLabel.new(id: label_id) } }
     let(:expected_hash_code) { Digest::SHA256.hexdigest("#{instance.class.identifier}-#{label_id}") }
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:project) { create(:project, :repository) }
+    let_it_be(:label) { create(:label, project: project) }
+    let_it_be(:record_with_data) { create(:labeled_merge_request, :unique_branches, source_project: project, labels: [label]) }
+    let_it_be(:record_without_data) { create(:merge_request) }
+    let_it_be(:user) { project.owner }
+
+    let(:params) { { label: label } }
+
+    before(:context) do
+      Sidekiq::Worker.skipping_transaction_check do
+        MergeRequests::UpdateService.new(project: project, current_user: user, params: { label_ids: [] }).execute(record_with_data)
+      end
+    end
+  end
 end

ee/spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_last_edited_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestLastEdited do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request, last_edited_at: Time.current) }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

lib/gitlab/analytics/cycle_analytics/stage_events/code_stage_start.rb

@@ -53,6 +53,10 @@ module Gitlab
               .on(mr_metrics_table[:merge_request_id].eq(mr_table[:id]))
               .join_sources
           end
+
+          def include_in(query)
+            query.left_joins(merge_requests_closing_issues: { issue: [:metrics] }, metrics: [])
+          end
         end
       end
     end

lib/gitlab/analytics/cycle_analytics/stage_events/issue_deployed_to_production.rb

@@ -26,6 +26,10 @@ module Gitlab
             query.joins(merge_requests_closing_issues: { merge_request: [:metrics] }).where(mr_metrics_table[:first_deployed_to_production_at].gteq(mr_table[:created_at]))
           end
           # rubocop: enable CodeReuse/ActiveRecord
+
+          def include_in(query)
+            query.left_joins(merge_requests_closing_issues: { merge_request: [:metrics] })
+          end
         end
       end
     end

lib/gitlab/analytics/cycle_analytics/stage_events/metrics_based_stage_event.rb

@@ -20,6 +20,10 @@ module Gitlab
           def column_list
             [timestamp_projection]
           end
+
+          def include_in(query)
+            super.left_joins(:metrics)
+          end
         end
       end
     end

lib/gitlab/analytics/cycle_analytics/stage_events/stage_event.rb

@@ -61,6 +61,10 @@ module Gitlab
           end
           # rubocop: enable CodeReuse/ActiveRecord
 
+          def include_in(query)
+            query
+          end
+
           def self.label_based?
             false
           end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/code_stage_start_spec.rb

@@ -19,4 +19,16 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::CodeStageStart do
     expect(records).to eq([merge_request])
     expect(records).not_to include(other_merge_request)
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) do
+      mr_closing_issue = FactoryBot.create(:merge_requests_closing_issues)
+      issue = mr_closing_issue.issue
+      issue.metrics.update!(first_mentioned_in_commit_at: Time.current)
+
+      mr_closing_issue.merge_request
+    end
+
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_created_spec.rb

@@ -4,4 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueCreated do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_deployed_to_production_spec.rb

@@ -4,4 +4,16 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueDeployedToProduction do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) do
+      mr_closing_issue = FactoryBot.create(:merge_requests_closing_issues)
+      mr = mr_closing_issue.merge_request
+      mr.metrics.update!(first_deployed_to_production_at: Time.current)
+
+      mr_closing_issue.issue
+    end
+
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_first_mentioned_in_commit_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueFirstMentionedInCommit do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue).tap { |i| i.metrics.update!(first_mentioned_in_commit_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/issue_stage_end_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::IssueStageEnd do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue).tap { |i| i.metrics.update!(first_added_to_board_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_created_spec.rb

@@ -4,4 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestCreated do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_first_deployed_to_production_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestFirstDeployedToProduction do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(first_deployed_to_production_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_last_build_finished_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestLastBuildFinished do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(latest_build_finished_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_last_build_started_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestLastBuildStarted do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(latest_build_started_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/merge_request_merged_spec.rb

@@ -4,4 +4,9 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::MergeRequestMerged do
   it_behaves_like 'value stream analytics event'
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:merge_request).tap { |mr| mr.metrics.update!(merged_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:merge_request) }
+  end
 end

spec/lib/gitlab/analytics/cycle_analytics/stage_events/plan_stage_start_spec.rb

@@ -21,4 +21,9 @@ RSpec.describe Gitlab::Analytics::CycleAnalytics::StageEvents::PlanStageStart do
     expect(records).to match_array([issue1, issue2])
     expect(records).not_to include(issue_without_metrics)
   end
+
+  it_behaves_like 'LEFT JOIN-able value stream analytics event' do
+    let_it_be(:record_with_data) { create(:issue).tap { |i| i.metrics.update!(first_added_to_board_at: Time.current) } }
+    let_it_be(:record_without_data) { create(:issue) }
+  end
 end

spec/support/shared_examples/lib/gitlab/cycle_analytics/event_shared_examples.rb

@@ -33,3 +33,38 @@ RSpec.shared_examples_for 'value stream analytics event' do
     end
   end
 end
+
+RSpec.shared_examples_for 'LEFT JOIN-able value stream analytics event' do
+  let(:params) { {} }
+  let(:instance) { described_class.new(params) }
+  let(:record_with_data) { nil }
+  let(:record_without_data) { nil }
+  let(:scope) { instance.object_type.all }
+
+  let(:records) do
+    scope_with_left_join = instance.include_in(scope)
+    scope_with_left_join.select(scope.model.arel_table[:id], instance.timestamp_projection.as('timestamp_column_data')).to_a
+  end
+
+  it 'can use the event as LEFT JOIN' do
+    expected_record_count = record_without_data.nil? ? 1 : 2
+
+    expect(records.count).to eq(expected_record_count)
+  end
+
+  context 'when looking at the record with data' do
+    subject(:record) { records.to_a.find { |r| r.id == record_with_data.id } }
+
+    it 'contains the timestamp expression' do
+      expect(record.timestamp_column_data).not_to eq(nil)
+    end
+  end
+
+  context 'when looking at the record without data' do
+    subject(:record) { records.to_a.find { |r| r.id == record_without_data.id } }
+
+    it 'returns nil for the timestamp expression' do
+      expect(record.timestamp_column_data).to eq(nil) if record_without_data
+    end
+  end
+end