Create a system note after tagging a commit

app/models/system_note_metadata.rb

@@ -15,7 +15,7 @@ class SystemNoteMetadata < ActiveRecord::Base
     commit description merge confidential visible label assignee cross_reference
     title time_tracking branch milestone discussion task moved
     opened closed merged duplicate locked unlocked
-    outdated
+    outdated tag
   ].freeze
 
   validates :note, presence: true

app/services/commits/update_service.rb

@@ -20,7 +20,8 @@ module Commits
         .new(commit.project, current_user)
         .execute(tag_name, commit.sha, message, release_description)
 
-      if result[:status]
+      if result[:status] == :success && (tag = result[:tag])
+        SystemNoteService.tag_commit(commit, commit.project, current_user, tag.name)
         commit
       end
     end

app/services/system_note_service.rb

@@ -32,6 +32,20 @@ module SystemNoteService
     create_note(NoteSummary.new(noteable, project, author, body, action: 'commit', commit_count: total_count))
   end
 
+  # Called when a commit was tagged
+  #
+  # noteable  - Noteable object
+  # project   - Project owning noteable
+  # author    - User performing the tag
+  # tag_name  - The created tag name
+  #
+  # Returns the created Note object
+  def tag_commit(noteable, project, author, tag_name)
+    body = "tagged commit #{noteable.sha} to `#{tag_name}`"
+
+    create_note(NoteSummary.new(noteable, project, author, body, action: 'tag'))
+  end
+
   # Called when the assignee of a Noteable is changed or removed
   #
   # noteable - Noteable object

spec/services/commits/update_service_spec.rb

@@ -22,11 +22,26 @@ describe Commits::UpdateService do
       end
 
       it 'tags a commit' do
+        tag_double = double(name: opts[:tag_name])
         tag_stub = instance_double(Tags::CreateService)
         allow(Tags::CreateService).to receive(:new).and_return(tag_stub)
         allow(tag_stub).to receive(:execute)
           .with(opts[:tag_name], commit.sha, opts[:tag_message], nil)
-          .and_return({ status: :success })
+          .and_return({ status: :success, tag: tag_double })
+
+        expect(SystemNoteService).to receive(:tag_commit).with(commit, project, user, opts[:tag_name])
+
+        service.execute(commit)
+      end
+
+      it 'fails to tag the commit' do
+        tag_stub = instance_double(Tags::CreateService)
+        allow(Tags::CreateService).to receive(:new).and_return(tag_stub)
+        allow(tag_stub).to receive(:execute)
+          .with(opts[:tag_name], commit.sha, opts[:tag_message], nil)
+          .and_return({ status: :error })
+
+        expect(SystemNoteService).not_to receive(:tag_commit)
 
         service.execute(commit)
       end
@@ -39,6 +54,7 @@ describe Commits::UpdateService do
 
       it 'does not call the tag create service' do
         expect(Tags::CreateService).not_to receive(:new)
+        expect(SystemNoteService).not_to receive(:tag_commit)
 
         service.execute(commit)
       end

spec/services/system_note_service_spec.rb

@@ -108,6 +108,23 @@ describe SystemNoteService do
     end
   end
 
+  describe '.tag_commit' do
+    let(:noteable) do
+      project.commit
+    end
+    let(:tag_name) { '1.2.3' }
+
+    subject { described_class.tag_commit(noteable, project, author, tag_name) }
+
+    it_behaves_like 'a system note' do
+      let(:action) { 'tag' }
+    end
+
+    it 'sets the note text' do
+      expect(subject.note).to eq "tagged commit #{noteable.sha} to `#{tag_name}`"
+    end
+  end
+
   describe '.change_assignee' do
     subject { described_class.change_assignee(noteable, project, author, assignee) }