Track epic cross reference on usage ping

Record epic cross reference event

app/services/system_notes/issuables_service.rb

@@ -178,8 +178,7 @@ module SystemNotes
       if noteable.is_a?(ExternalIssue)
         noteable.project.external_issue_tracker.create_cross_reference_note(noteable, mentioner, author)
       else
-        issue_activity_counter.track_issue_cross_referenced_action(author: author) if noteable.is_a?(Issue)
-
+        track_cross_reference_action
         create_note(NoteSummary.new(noteable, noteable.project, author, body, action: 'cross_reference'))
       end
     end
@@ -414,6 +413,10 @@ module SystemNotes
     def issue_activity_counter
       Gitlab::UsageDataCounters::IssueActivityUniqueCounter
     end
+
+    def track_cross_reference_action
+      issue_activity_counter.track_issue_cross_referenced_action(author: author) if noteable.is_a?(Issue)
+    end
   end
 end
 

doc/development/usage_ping/dictionary.md

@@ -10292,6 +10292,30 @@ Status: `data_available`
 
 Tiers: `premium`, `ultimate`
 
+### `redis_hll_counters.epics_usage.g_project_management_epic_cross_referenced_monthly`
+
+Count of MAU cross referencing epics
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_28d/20210430174100_g_project_management_epic_cross_referenced_monthly.yml)
+
+Group: `group::product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
+### `redis_hll_counters.epics_usage.g_project_management_epic_cross_referenced_weekly`
+
+Counts of WAU cross referencing epics
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_7d/20210430173650_g_project_management_epic_cross_referenced_weekly.yml)
+
+Group: `group::product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
 ### `redis_hll_counters.epics_usage.g_project_management_epic_destroyed_monthly`
 
 Count of MAU destroying epics

ee/app/services/ee/system_notes/issuables_service.rb

@@ -2,6 +2,7 @@
 module EE
   module SystemNotes
     module IssuablesService
+      extend ::Gitlab::Utils::Override
       # Called when the health_status of an Issue is changed
       #
       # Example Note text:
@@ -33,6 +34,15 @@ module EE
 
         create_note(NoteSummary.new(noteable, project, author, body, action: 'published'))
       end
+
+      override :track_cross_reference_action
+      def track_cross_reference_action
+        super
+
+        counter = ::Gitlab::UsageDataCounters::EpicActivityUniqueCounter
+
+        counter.track_epic_cross_referenced(author: author) if noteable.is_a?(Epic)
+      end
     end
   end
 end

ee/changelogs/unreleased/issue_292253-track_epic_cross_reference.yml

+---
+title: Track epic cross reference on usage ping
+merge_request: 59804
+author:
+type: other

ee/config/metrics/counts_28d/20210430174100_g_project_management_epic_cross_referenced_monthly.yml

+---
+# Name of this metric contains g_project_management prefix
+# because we are using the same slot from issue_tracking to
+# allow data aggregation.
+key_path: redis_hll_counters.epics_usage.g_project_management_epic_cross_referenced_monthly
+description: Count of MAU cross referencing epics
+product_section: dev
+product_stage: plan
+product_group: group::product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.12"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59804
+time_frame: 28d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/config/metrics/counts_7d/20210430173650_g_project_management_epic_cross_referenced_weekly.yml

+---
+# Name of this metric contains g_project_management prefix
+# because we are using the same slot from issue_tracking to
+# allow data aggregation.
+key_path: redis_hll_counters.epics_usage.g_project_management_epic_cross_referenced_weekly
+description: Counts of WAU cross referencing epics
+product_section: dev
+product_stage: plan
+product_group: group::product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.12"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59804
+time_frame: 7d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/lib/gitlab/usage_data_counters/epic_activity_unique_counter.rb

@@ -32,6 +32,7 @@ module Gitlab
       EPIC_DESTROYED = 'g_project_management_epic_destroyed'
       EPIC_TASK_CHECKED = 'project_management_users_checking_epic_task'
       EPIC_TASK_UNCHECKED = 'project_management_users_unchecking_epic_task'
+      EPIC_CROSS_REFERENCED = 'g_project_management_epic_cross_referenced'
 
       class << self
         def track_epic_created_action(author:)
@@ -134,6 +135,10 @@ module Gitlab
           track_unique_action(EPIC_TASK_UNCHECKED, author)
         end
 
+        def track_epic_cross_referenced(author:)
+          track_unique_action(EPIC_CROSS_REFERENCED, author)
+        end
+
         private
 
         def track_unique_action(action, author)

ee/spec/lib/gitlab/usage_data_counters/epic_activity_unique_counter_spec.rb

@@ -303,4 +303,16 @@ RSpec.describe Gitlab::UsageDataCounters::EpicActivityUniqueCounter, :clean_gitl
 
     it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
   end
+
+  context 'for epic cross reference' do
+    def track_action(params)
+      described_class.track_epic_cross_referenced(**params)
+    end
+
+    it_behaves_like 'a daily tracked issuable event' do
+      let(:action) { described_class::EPIC_CROSS_REFERENCED }
+    end
+
+    it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
+  end
 end

ee/spec/services/ee/system_notes/issuables_service_spec.rb

@@ -60,4 +60,32 @@ RSpec.describe ::SystemNotes::IssuablesService do
       expect(subject.note).to eq 'published this issue to the status page'
     end
   end
+
+  describe '#cross_reference' do
+    let(:mentioner) { create(:issue, project: project) }
+
+    subject { service.cross_reference(mentioner) }
+
+    context 'when noteable is an epic' do
+      let(:noteable) { epic }
+
+      it_behaves_like 'a system note', exclude_project: true do
+        let(:action) { 'cross_reference' }
+      end
+
+      it 'tracks epic cross reference event in usage ping' do
+        expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter).to receive(:track_epic_cross_referenced).with(author: author)
+
+        subject
+      end
+    end
+
+    context 'when notable is not an epic' do
+      it 'does not tracks epic cross reference event in usage ping' do
+        expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter).not_to receive(:track_epic_cross_referenced)
+
+        subject
+      end
+    end
+  end
 end

lib/gitlab/usage_data_counters/known_events/epic_events.yml

@@ -162,3 +162,9 @@
   redis_slot: project_management
   aggregation: daily
   feature_flag: track_epics_activity
+
+- name: g_project_management_epic_cross_referenced
+  category: epics_usage
+  redis_slot: project_management
+  aggregation: daily
+  feature_flag: track_epics_activity