Add task item status change events

config/feature_flags/development/usage_data_i_code_review_user_toggled_task_item_status.yml

+---
+name: usage_data_i_code_review_user_toggled_task_item_status
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/issues/320851
+rollout_issue_url:
+milestone: '13.9'
+type: development
+group: group::code review
+default_enabled: true

lib/gitlab/usage_data_counters/known_events/code_review_events.yml

@@ -14,6 +14,11 @@
   category: code_review
   aggregation: weekly
   feature_flag: usage_data_i_code_review_mr_single_file_diffs
+- name: i_code_review_user_toggled_task_item_status
+  redis_slot: code_review
+  category: code_review
+  aggregation: weekly
+  feature_flag: usage_data_i_code_review_user_toggled_task_item_status
 - name: i_code_review_user_create_mr
   redis_slot: code_review
   category: code_review

lib/gitlab/usage_data_counters/merge_request_activity_unique_counter.rb

@@ -28,6 +28,7 @@ module Gitlab
       MR_UNRESOLVE_THREAD_ACTION = 'i_code_review_user_unresolve_thread'
       MR_ASSIGNED_USERS_ACTION = 'i_code_review_user_assigned'
       MR_REVIEW_REQUESTED_USERS_ACTION = 'i_code_review_user_review_requested'
+      MR_TASK_ITEM_STATUS_CHANGED_ACTION = 'i_code_review_user_toggled_task_item_status'
       MR_APPROVAL_RULE_ADDED_USERS_ACTION = 'i_code_review_user_approval_rule_added'
       MR_APPROVAL_RULE_EDITED_USERS_ACTION = 'i_code_review_user_approval_rule_edited'
       MR_APPROVAL_RULE_DELETED_USERS_ACTION = 'i_code_review_user_approval_rule_deleted'
@@ -143,6 +144,10 @@ module Gitlab
           track_unique_action_by_user(MR_APPROVAL_RULE_DELETED_USERS_ACTION, user)
         end
 
+        def track_task_item_status_changed(user:)
+          track_unique_action_by_user(MR_TASK_ITEM_STATUS_CHANGED_ACTION, user)
+        end
+
         private
 
         def track_unique_action_by_merge_request(action, merge_request)

spec/lib/gitlab/usage_data_counters/merge_request_activity_unique_counter_spec.rb

@@ -237,6 +237,14 @@ RSpec.describe Gitlab::UsageDataCounters::MergeRequestActivityUniqueCounter, :cl
     end
   end
 
+  describe '.track_task_item_status_changed' do
+    subject { described_class.track_task_item_status_changed(user: user) }
+
+    it_behaves_like 'a tracked merge request unique event' do
+      let(:action) { described_class::MR_TASK_ITEM_STATUS_CHANGED_ACTION }
+    end
+  end
+
   describe '.track_users_review_requested' do
     subject { described_class.track_users_review_requested(users: [user]) }