Track epic set start date as fixed or inherited via usage ping

- Add usage ping metrics files

doc/development/usage_ping/dictionary.md

@@ -9836,6 +9836,54 @@ Status: `implemented`
 
 Tiers: `premium`, `ultimate`
 
+### `redis_hll_counters.epics_usage.g_project_management_users_setting_epic_start_date_as_fixed_monthly`
+
+Counts of MAU setting epic start date as fixed
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_28d/20210315055624_g_project_management_users_setting_epic_start_date_as_fixed_monthly.yml)
+
+Group: `group:product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
+### `redis_hll_counters.epics_usage.g_project_management_users_setting_epic_start_date_as_fixed_weekly`
+
+Counts of WAU setting epic start date as fixed
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_7d/20210315054905_g_project_management_users_setting_epic_start_date_as_fixed_weekly.yml)
+
+Group: `group:product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
+### `redis_hll_counters.epics_usage.g_project_management_users_setting_epic_start_date_as_inherited_monthly`
+
+Counts of MAU setting epic start date as inherited
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_28d/20210315055439_g_project_management_users_setting_epic_start_date_as_inherited_monthly.yml)
+
+Group: `group:product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
+### `redis_hll_counters.epics_usage.g_project_management_users_setting_epic_start_date_as_inherited_weekly`
+
+Counts of WAU setting epic start date as inherited
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_7d/20210315055342_g_project_management_users_setting_epic_start_date_as_inherited_weekly.yml)
+
+Group: `group:product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
 ### `redis_hll_counters.ide_edit.g_edit_by_sfe_monthly`
 
 Missing description

ee/app/services/epics/update_service.rb

@@ -18,6 +18,9 @@ module Epics
 
       if saved_change_to_epic_dates?(epic)
         Epics::UpdateDatesService.new([epic]).execute
+
+        track_start_date_fixed_events(epic)
+
         epic.reset
       end
 
@@ -51,6 +54,16 @@ module Epics
 
     private
 
+    def track_start_date_fixed_events(epic)
+      return unless epic.saved_changes.key?('start_date_is_fixed')
+
+      if epic.start_date_is_fixed?
+        ::Gitlab::UsageDataCounters::EpicActivityUniqueCounter.track_epic_start_date_set_as_fixed_action(author: current_user)
+      else
+        ::Gitlab::UsageDataCounters::EpicActivityUniqueCounter.track_epic_start_date_set_as_inherited_action(author: current_user)
+      end
+    end
+
     def saved_change_to_epic_dates?(epic)
       (epic.saved_changes.keys.map(&:to_sym) & EPIC_DATE_FIELDS).present?
     end

ee/changelogs/unreleased/292253-cablett-track-epic-start-date-fixed.yml

+---
+title: Track epic start date set to fixed or inherited via usage ping
+merge_request: 56619
+author:
+type: other

ee/config/metrics/counts_28d/20210315055439_g_project_management_users_setting_epic_start_date_as_inherited_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_users_setting_epic_start_date_as_inherited_monthly
+description: Counts of MAU setting epic start date as inherited
+product_section: dev
+product_stage: plan
+product_group: group:product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.11"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56619
+time_frame: 28d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/config/metrics/counts_28d/20210315055624_g_project_management_users_setting_epic_start_date_as_fixed_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_users_setting_epic_start_date_as_fixed_monthly
+description: Counts of MAU setting epic start date as fixed
+product_section: dev
+product_stage: plan
+product_group: group:product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.11"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56619
+time_frame: 28d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/config/metrics/counts_7d/20210315054905_g_project_management_users_setting_epic_start_date_as_fixed_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_users_setting_epic_start_date_as_fixed_weekly
+description: Counts of WAU setting epic start date as fixed
+product_section: dev
+product_stage: plan
+product_group: group:product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.11"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56619
+time_frame: 7d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/config/metrics/counts_7d/20210315055342_g_project_management_users_setting_epic_start_date_as_inherited_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_users_setting_epic_start_date_as_inherited_weekly
+description: Counts of WAU setting epic start date as inherited
+product_section: dev
+product_stage: plan
+product_group: group:product planning
+product_category: epics_usage
+value_type: number
+status: implemented
+milestone: "13.11"
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56619
+time_frame: 7d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate
+

ee/lib/gitlab/usage_data_counters/epic_activity_unique_counter.rb

@@ -8,6 +8,8 @@ module Gitlab
       # slot of issue events to allow data aggregation.
       # More information in: https://gitlab.com/gitlab-org/gitlab/-/issues/322405
       EPIC_CREATED = 'g_project_management_epic_created'
+      EPIC_START_DATE_SET_AS_FIXED = 'g_project_management_users_setting_epic_start_date_as_fixed'
+      EPIC_START_DATE_SET_AS_INHERITED = 'g_project_management_users_setting_epic_start_date_as_inherited'
       EPIC_NOTE_DESTROYED = 'g_project_management_users_destroying_epic_notes'
 
       class << self
@@ -19,6 +21,14 @@ module Gitlab
           track_unique_action(EPIC_NOTE_DESTROYED, author, time)
         end
 
+        def track_epic_start_date_set_as_fixed_action(author:, time: Time.zone.now)
+          track_unique_action(EPIC_START_DATE_SET_AS_FIXED, author, time)
+        end
+
+        def track_epic_start_date_set_as_inherited_action(author:, time: Time.zone.now)
+          track_unique_action(EPIC_START_DATE_SET_AS_INHERITED, author, time)
+        end
+
         private
 
         def track_unique_action(action, author, time)

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

@@ -31,4 +31,30 @@ 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 date modification events' do
+    context 'setting start date as fixed event' do
+      def track_action(params)
+        described_class.track_epic_start_date_set_as_fixed_action(**params)
+      end
+
+      it_behaves_like 'a daily tracked issuable event' do
+        let(:action) { described_class::EPIC_START_DATE_SET_AS_FIXED }
+      end
+
+      it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
+    end
+
+    context 'setting start date as inherited event' do
+      def track_action(params)
+        described_class.track_epic_start_date_set_as_inherited_action(**params)
+      end
+
+      it_behaves_like 'a daily tracked issuable event' do
+        let(:action) { described_class::EPIC_START_DATE_SET_AS_INHERITED }
+      end
+
+      it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
+    end
+  end
 end

ee/spec/services/epics/update_service_spec.rb

@@ -293,6 +293,20 @@ RSpec.describe Epics::UpdateService do
         end
       end
 
+      context 'epic start date fixed or inherited' do
+        it 'tracks the user action to set as fixed' do
+          expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter).to receive(:track_epic_start_date_set_as_fixed_action)
+
+          update_epic(start_date_is_fixed: true, start_date_fixed: Date.today)
+        end
+
+        it 'tracks the user action to set as inherited' do
+          expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter).to receive(:track_epic_start_date_set_as_inherited_action)
+
+          update_epic(start_date_is_fixed: false)
+        end
+      end
+
       context 'date fields are not updated' do
         it 'does not call UpdateDatesService' do
           expect(Epics::UpdateDatesService).not_to receive(:new)

lib/gitlab/usage_data_counters/known_events/epic_events.yml

@@ -14,3 +14,15 @@
   redis_slot: project_management
   aggregation: daily
   feature_flag: track_epics_activity
+
+- name: g_project_management_users_setting_epic_start_date_as_fixed
+  category: epics_usage
+  redis_slot: project_management
+  aggregation: daily
+  feature_flag: track_epics_activity
+
+- name: g_project_management_users_setting_epic_start_date_as_inherited
+  category: epics_usage
+  redis_slot: project_management
+  aggregation: daily
+  feature_flag: track_epics_activity