Fix timebox events to track only issue events

Also renames the hook to be more specific.
Also changes resource state event to make the hooks consistent.

app/models/resource_state_event.rb

@@ -11,7 +11,7 @@ class ResourceStateEvent < ResourceEvent
   # state is used for issue and merge request states.
   enum state: Issue.available_states.merge(MergeRequest.available_states).merge(reopened: 5)
 
-  after_save :usage_metrics
+  after_create :issue_usage_metrics
 
   def self.issuable_attrs
     %i(issue merge_request).freeze
@@ -27,7 +27,7 @@ class ResourceStateEvent < ResourceEvent
 
   private
 
-  def usage_metrics
+  def issue_usage_metrics
     return unless for_issue?
 
     case state

app/models/resource_timebox_event.rb

@@ -13,7 +13,7 @@ class ResourceTimeboxEvent < ResourceEvent
     remove: 2
   }
 
-  after_save :usage_metrics
+  after_create :issue_usage_metrics
 
   def self.issuable_attrs
     %i(issue merge_request).freeze
@@ -25,7 +25,13 @@ class ResourceTimeboxEvent < ResourceEvent
 
   private
 
-  def usage_metrics
+  def for_issue?
+    issue_id.present?
+  end
+
+  def issue_usage_metrics
+    return unless for_issue?
+
     case self
     when ResourceMilestoneEvent
       Gitlab::UsageDataCounters::IssueActivityUniqueCounter.track_issue_milestone_changed_action(author: user)

ee/app/models/ee/resource_timebox_event.rb

@@ -6,8 +6,10 @@ module EE
 
     private
 
-    override :usage_metrics
-    def usage_metrics
+    override :issue_usage_metrics
+    def issue_usage_metrics
+      return unless for_issue?
+
       case self
       when ResourceIterationEvent
         ::Gitlab::UsageDataCounters::IssueActivityUniqueCounter.track_issue_iteration_changed_action(author: user)

spec/models/resource_state_event_spec.rb

@@ -41,7 +41,7 @@ RSpec.describe ResourceStateEvent, type: :model do
   end
 
   context 'callbacks' do
-    describe '#usage_metrics' do
+    describe '#issue_usage_metrics' do
       it 'tracks closed issues' do
         expect(Gitlab::UsageDataCounters::IssueActivityUniqueCounter).to receive(:track_issue_closed_action)
 
@@ -53,6 +53,12 @@ RSpec.describe ResourceStateEvent, type: :model do
 
         create(described_class.name.underscore.to_sym, issue: issue, state: described_class.states[:reopened])
       end
+
+      it 'does not track merge requests' do
+        expect(Gitlab::UsageDataCounters::IssueActivityUniqueCounter).not_to receive(:track_issue_closed_action)
+
+        create(described_class.name.underscore.to_sym, merge_request: merge_request, state: described_class.states[:closed])
+      end
     end
   end
 end

spec/support/shared_examples/models/resource_timebox_event_shared_examples.rb

@@ -75,11 +75,17 @@ RSpec.shared_examples 'timebox resource event actions' do
 end
 
 RSpec.shared_examples 'timebox resource tracks issue metrics' do |type|
-  describe '#usage_metrics' do
-    it 'tracks usage' do
+  describe '#issue_usage_metrics' do
+    it 'tracks usage for issues' do
       expect(Gitlab::UsageDataCounters::IssueActivityUniqueCounter).to receive(:"track_issue_#{type}_changed_action")
 
       create(described_class.name.underscore.to_sym, issue: create(:issue))
     end
+
+    it 'does not track usage for merge requests' do
+      expect(Gitlab::UsageDataCounters::IssueActivityUniqueCounter).not_to receive(:"track_issue_#{type}_changed_action")
+
+      create(described_class.name.underscore.to_sym, merge_request: create(:merge_request))
+    end
   end
 end