Track epic labels change action on usage ping

https://gitlab.com/gitlab-org/gitlab/-/issues/292253

doc/development/usage_ping/dictionary.md

@@ -9956,6 +9956,30 @@ Status: `implemented`
 
 Tiers: `premium`, `ultimate`
 
+### `redis_hll_counters.epics_usage.g_project_management_epic_users_changing_labels_monthly`
+
+Count of MAU chaging the epic lables
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_28d/20210312195730_g_project_management_epic_labels_monthly.yml)
+
+Group: `group::product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
+### `redis_hll_counters.epics_usage.g_project_management_epic_users_changing_labels_weekly`
+
+Count of WAU chaging the epic lables
+
+[YAML definition](https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/config/metrics/counts_7d/20210312195849_g_project_management_epic_labels_weekly.yml)
+
+Group: `group::product planning`
+
+Status: `implemented`
+
+Tiers: `premium`, `ultimate`
+
 ### `redis_hll_counters.epics_usage.g_project_management_issue_promoted_to_epic_monthly`
 
 Count of MAU promoting issues to epics

ee/app/services/ee/resource_events/change_labels_service.rb

@@ -6,6 +6,13 @@ module EE
       extend ActiveSupport::Concern
       extend ::Gitlab::Utils::Override
 
+      override :execute
+      def execute(added_labels: [], removed_labels: [])
+        super
+
+        ::Gitlab::UsageDataCounters::EpicActivityUniqueCounter.track_epic_labels_changed_action(author: user) if resource.is_a?(Epic)
+      end
+
       override :resource_column
       def resource_column(resource)
         resource.is_a?(Epic) ? :epic_id : super

ee/changelogs/unreleased/292253-counts-epic-labels.yml

+---
+title: Track epic labels change action on usage ping
+merge_request: 56571
+author:
+type: other

ee/config/metrics/counts_28d/20210312195730_g_project_management_epic_labels_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_users_changing_labels_monthly
+description: Count of MAU chaging the epic lables
+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/56571
+time_frame: 28d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/config/metrics/counts_7d/20210312195849_g_project_management_epic_labels_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_users_changing_labels_weekly
+description: Count of WAU chaging the epic lables
+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/56571
+time_frame: 7d
+data_source: redis_hll
+distribution:
+- ee
+tier:
+- premium
+- ultimate

ee/lib/gitlab/usage_data_counters/epic_activity_unique_counter.rb

@@ -26,6 +26,7 @@ module Gitlab
       ISSUE_PROMOTED_TO_EPIC = 'g_project_management_issue_promoted_to_epic'
       EPIC_CONFIDENTIAL = 'g_project_management_users_setting_epic_confidential'
       EPIC_VISIBLE = 'g_project_management_users_setting_epic_visible'
+      EPIC_LABELS = 'g_project_management_epic_users_changing_labels'
 
       class << self
         def track_epic_created_action(author:)
@@ -104,6 +105,10 @@ module Gitlab
           track_unique_action(EPIC_VISIBLE, author)
         end
 
+        def track_epic_labels_changed_action(author:)
+          track_unique_action(EPIC_LABELS, author)
+        end
+
         private
 
         def track_unique_action(action, author)

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

@@ -208,6 +208,16 @@ RSpec.describe Gitlab::UsageDataCounters::EpicActivityUniqueCounter, :clean_gitl
     it_behaves_like 'a daily tracked issuable event' do
       let(:action) { described_class::EPIC_ISSUE_ADDED }
     end
+  end
+
+  context 'for changing labels epic event' do
+    def track_action(params)
+      described_class.track_epic_labels_changed_action(**params)
+    end
+
+    it_behaves_like 'a daily tracked issuable event' do
+      let(:action) { described_class::EPIC_LABELS }
+    end
 
     it_behaves_like 'does not track when feature flag is disabled', :track_epics_activity
   end

ee/spec/services/ee/resource_events/change_labels_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ResourceEvents::ChangeLabelsService do
+  let_it_be(:group) { create(:group) }
+  let_it_be(:user)  { create(:user) }
+  let_it_be(:labels) { create_list(:group_label, 2, group: group) }
+
+  let(:resource) { create(:epic, group: group) }
+
+  describe '.execute' do
+    subject { described_class.new(resource, user).execute(added_labels: added, removed_labels: removed) }
+
+    context 'when adding a label' do
+      let(:added)   { [labels[0]] }
+      let(:removed) { [] }
+
+      it 'tracks the label change' do
+        expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter)
+          .to receive(:track_epic_labels_changed_action).with(author: user)
+
+        subject
+      end
+    end
+
+    context 'when removing a label' do
+      let(:added)   { [] }
+      let(:removed) { [labels[1]] }
+
+      it 'tracks the label change' do
+        expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter)
+          .to receive(:track_epic_labels_changed_action).with(author: user)
+
+        subject
+      end
+    end
+
+    context 'when both adding and removing labels' do
+      let(:added)   { [labels[0]] }
+      let(:removed) { [labels[1]] }
+
+      it 'tracks the label change' do
+        expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter)
+          .to receive(:track_epic_labels_changed_action).with(author: user)
+
+        subject
+      end
+    end
+  end
+end

ee/spec/services/epics/update_service_spec.rb

@@ -220,19 +220,30 @@ RSpec.describe Epics::UpdateService do
             user: user2)
         end
 
+        subject { update_epic(label_ids: [label.id]) }
+
         before do
           group.add_developer(user)
-
-          update_epic(label_ids: [label.id])
         end
 
         it 'marks todo as done for a user who added a label' do
+          subject
+
           expect(todo1.reload.state).to eq('done')
         end
 
         it 'does not mark todos as done for other users' do
+          subject
+
           expect(todo2.reload.state).to eq('pending')
         end
+
+        it 'tracks the label change' do
+          expect(::Gitlab::UsageDataCounters::EpicActivityUniqueCounter)
+            .to receive(:track_epic_labels_changed_action).with(author: user)
+
+          subject
+        end
       end
 
       context 'mentioning a group in epic description' do

lib/gitlab/usage_data_counters/known_events/epic_events.yml

@@ -122,3 +122,9 @@
   redis_slot: project_management
   aggregation: daily
   feature_flag: track_epics_activity
+
+- name: g_project_management_epic_users_changing_labels
+  category: epics_usage
+  redis_slot: project_management
+  aggregation: daily
+  feature_flag: track_epics_activity