Change Note#to_ability_name to 'note'

This is to be more consistent as there is already a :read_note policy in
NotePolicy. To keep other behaviour the same we've introduced a
Note#noteable_ability_name that is used anywhere this was expected.

app/models/discussion.rb

@@ -16,6 +16,7 @@ class Discussion
             :commit_id,
             :for_commit?,
             :for_merge_request?,
+            :noteable_ability_name,
             :to_ability_name,
             :editable?,
             :visible_for?,

app/models/note.rb

@@ -361,6 +361,10 @@ class Note < ApplicationRecord
   end
   def to_ability_name
+    model_name.singular
+  end
+
+  def noteable_ability_name
     for_snippet? ? noteable.class.name.underscore : noteable_type.demodulize.underscore
   end

app/policies/note_policy.rb

@@ -9,7 +9,7 @@ class NotePolicy < BasePolicy
   condition(:editable, scope: :subject) { @subject.editable? }
-  condition(:can_read_noteable) { can?(:"read_#{@subject.to_ability_name}") }
+  condition(:can_read_noteable) { can?(:"read_#{@subject.noteable_ability_name}") }
   condition(:is_visible) { @subject.visible_for?(@user) }

app/services/notification_service.rb

@@ -281,7 +281,7 @@ class NotificationService
   end
   def send_new_note_notifications(note)
-    notify_method = "note_#{note.to_ability_name}_email".to_sym
+    notify_method = "note_#{note.noteable_ability_name}_email".to_sym
     recipients = NotificationRecipientService.build_new_note_recipients(note)
     recipients.each do |recipient|

spec/models/note_spec.rb

@@ -578,24 +578,30 @@ describe Note do
   end
   describe '#to_ability_name' do
-    it 'returns snippet for a project snippet note' do
-      expect(build(:note_on_project_snippet).to_ability_name).to eq('project_snippet')
+    it 'returns note' do
+      expect(build(:note).to_ability_name).to eq('note')
+    end
+  end
+
+  describe '#noteable_ability_name' do
+    it 'returns project_snippet for a project snippet note' do
+      expect(build(:note_on_project_snippet).noteable_ability_name).to eq('project_snippet')
     end
     it 'returns personal_snippet for a personal snippet note' do
-      expect(build(:note_on_personal_snippet).to_ability_name).to eq('personal_snippet')
+      expect(build(:note_on_personal_snippet).noteable_ability_name).to eq('personal_snippet')
     end
     it 'returns merge_request for an MR note' do
-      expect(build(:note_on_merge_request).to_ability_name).to eq('merge_request')
+      expect(build(:note_on_merge_request).noteable_ability_name).to eq('merge_request')
     end
     it 'returns issue for an issue note' do
-      expect(build(:note_on_issue).to_ability_name).to eq('issue')
+      expect(build(:note_on_issue).noteable_ability_name).to eq('issue')
     end
-    it 'returns issue for a commit note' do
-      expect(build(:note_on_commit).to_ability_name).to eq('commit')
+    it 'returns commit for a commit note' do
+      expect(build(:note_on_commit).noteable_ability_name).to eq('commit')
     end
   end