Annotate merge request cherry-picks

When picking a merge_commit, it will be annotated with a system note.

This feature is behind the :track_mr_picking feature flag

app/helpers/system_note_helper.rb

@@ -2,6 +2,7 @@
 
 module SystemNoteHelper
   ICON_NAMES_BY_ACTION = {
+    'cherry_pick' => 'link',
     'commit' => 'commit',
     'description' => 'pencil-square',
     'merge' => 'git-merge',

app/models/merge_request.rb

@@ -228,6 +228,9 @@ class MergeRequest < ApplicationRecord
   scope :by_merge_commit_sha, -> (sha) do
     where(merge_commit_sha: sha)
   end
+  scope :by_cherry_pick_sha, -> (sha) do
+    joins(:notes).where(notes: { commit_id: sha })
+  end
   scope :join_project, -> { joins(:target_project) }
   scope :references_project, -> { references(:target_project) }
   scope :with_api_entity_associations, -> {

app/models/system_note_metadata.rb

@@ -17,7 +17,7 @@ class SystemNoteMetadata < ApplicationRecord
     commit description merge confidential visible label assignee cross_reference
     title time_tracking branch milestone discussion task moved
     opened closed merged duplicate locked unlocked
-    outdated tag due_date pinned_embed
+    outdated tag due_date pinned_embed cherry_pick
   ].freeze
 
   validates :note, presence: true

app/services/commits/cherry_pick_service.rb

@@ -3,7 +3,24 @@
 module Commits
   class CherryPickService < ChangeService
     def create_commit!
-      commit_change(:cherry_pick)
+      commit_change(:cherry_pick).tap do |sha|
+        track_mr_picking(sha)
+      end
+    end
+
+    private
+
+    def track_mr_picking(pick_sha)
+      return unless Feature.enabled?(:track_mr_picking, project)
+
+      merge_request = project.merge_requests.by_merge_commit_sha(@commit.sha).first
+      return unless merge_request
+
+      ::SystemNotes::MergeRequestsService.new(
+        noteable: merge_request,
+        project: project,
+        author: current_user
+      ).picked_into_branch(@branch_name, pick_sha)
     end
   end
 end

app/services/deployments/link_merge_requests_service.rb

@@ -38,6 +38,8 @@ module Deployments
         .commits_between(from, to)
         .map(&:id)
 
+      track_mr_picking = Feature.enabled?(:track_mr_picking, project)
+
       # For some projects the list of commits to deploy may be very large. To
       # ensure we do not end up running SQL queries with thousands of WHERE IN
       # values, we run one query per a certain number of commits.
@@ -50,6 +52,13 @@ module Deployments
           project.merge_requests.merged.by_merge_commit_sha(slice)
 
         deployment.link_merge_requests(merge_requests)
+
+        next unless track_mr_picking
+
+        picked_merge_requests =
+          project.merge_requests.by_cherry_pick_sha(slice)
+
+        deployment.link_merge_requests(picked_merge_requests)
       end
     end
 

app/services/system_notes/merge_requests_service.rb

@@ -139,6 +139,17 @@ module SystemNotes
 
       create_note(NoteSummary.new(noteable, project, author, body, action: 'merge'))
     end
+
+    def picked_into_branch(branch_name, pick_commit)
+      link = url_helpers.project_tree_path(project, branch_name)
+
+      body = "picked this merge request into branch [`#{branch_name}`](#{link}) with commit #{pick_commit}"
+
+      summary = NoteSummary.new(noteable, project, author, body, action: 'cherry_pick')
+      summary.note[:commit_id] = pick_commit
+
+      create_note(summary)
+    end
   end
 end
 

spec/factories/notes.rb

@@ -29,6 +29,11 @@ FactoryBot.define do
       end
     end
 
+    factory :track_mr_picking_note, traits: [:on_merge_request, :system] do
+      association :system_note_metadata, action: 'cherry_pick'
+      commit_id { RepoHelpers.sample_commit.id }
+    end
+
     factory :discussion_note_on_issue, traits: [:on_issue], class: 'DiscussionNote'
 
     factory :discussion_note_on_commit, traits: [:on_commit], class: 'DiscussionNote'

spec/models/merge_request_spec.rb

@@ -327,6 +327,16 @@ describe MergeRequest do
     end
   end
 
+  describe '.by_cherry_pick_sha' do
+    it 'returns merge requests that match the given merge commit' do
+      note = create(:track_mr_picking_note, commit_id: '456abc')
+
+      create(:track_mr_picking_note, commit_id: '456def')
+
+      expect(described_class.by_cherry_pick_sha('456abc')).to eq([note.noteable])
+    end
+  end
+
   describe '.in_projects' do
     it 'returns the merge requests for a set of projects' do
       expect(described_class.in_projects(Project.all)).to eq([subject])

spec/requests/api/deployments_spec.rb

@@ -122,7 +122,29 @@ describe API::Deployments do
 
   describe 'POST /projects/:id/deployments' do
     let!(:project) { create(:project, :repository) }
-    let(:sha) { 'b83d6e391c22777fca1ed3012fce84f633d7fed0' }
+    # *   ddd0f15ae83993f5cb66a927a28673882e99100b (HEAD -> master, origin/master, origin/HEAD) Merge branch 'po-fix-test-en
+    # |\
+    # | * 2d1db523e11e777e49377cfb22d368deec3f0793 Correct test_env.rb path for adding branch
+    # |/
+    # *   1e292f8fedd741b75372e19097c76d327140c312 Merge branch 'cherry-pick-ce369011' into 'master'
+
+    let_it_be(:sha) { 'ddd0f15ae83993f5cb66a927a28673882e99100b' }
+    let_it_be(:first_deployment_sha) { '1e292f8fedd741b75372e19097c76d327140c312' }
+
+    before do
+      # Creating the first deployment is an edge-case that is already covered by unit testing,
+      # here we want to see the behavior of a running system so we create a first deployment
+      post(
+        api("/projects/#{project.id}/deployments", user),
+        params: {
+          environment: 'production',
+          sha: first_deployment_sha,
+          ref: 'master',
+          tag: false,
+          status: 'success'
+        }
+      )
+    end
 
     context 'as a maintainer' do
       it 'creates a new deployment' do
@@ -163,6 +185,7 @@ describe API::Deployments do
         mr = create(
           :merge_request,
           :merged,
+          merge_commit_sha: sha,
           target_project: project,
           source_project: project,
           target_branch: 'master',
@@ -215,6 +238,7 @@ describe API::Deployments do
         mr = create(
           :merge_request,
           :merged,
+          merge_commit_sha: sha,
           target_project: project,
           source_project: project,
           target_branch: 'master',
@@ -236,6 +260,43 @@ describe API::Deployments do
 
         expect(deploy.merge_requests).to eq([mr])
       end
+
+      it 'links any picked merge requests to the deployment', :sidekiq_inline do
+        mr = create(
+          :merge_request,
+          :merged,
+          merge_commit_sha: sha,
+          target_project: project,
+          source_project: project,
+          target_branch: 'master',
+          source_branch: 'foo'
+        )
+
+        # we branch from the previous deployment and cherry-pick mr into the new branch
+        branch = project.repository.add_branch(developer, 'stable', first_deployment_sha)
+        expect(branch).not_to be_nil
+
+        result = ::Commits::CherryPickService
+                   .new(project, developer, commit: mr.merge_commit, start_branch: 'stable', branch_name: 'stable')
+                   .execute
+        expect(result[:status]).to eq(:success), result[:message]
+
+        pick_sha = result[:result]
+
+        post(
+          api("/projects/#{project.id}/deployments", developer),
+          params: {
+            environment: 'production',
+            sha: pick_sha,
+            ref: 'stable',
+            tag: false,
+            status: 'success'
+          }
+        )
+
+        deploy = project.deployments.last
+        expect(deploy.merge_requests).to eq([mr])
+      end
     end
 
     context 'as non member' do

spec/services/commits/cherry_pick_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Commits::CherryPickService do
+  let(:project) { create(:project, :repository) }
+  # *   ddd0f15ae83993f5cb66a927a28673882e99100b (HEAD -> master, origin/master, origin/HEAD) Merge branch 'po-fix-test-en
+  # |\
+  # | * 2d1db523e11e777e49377cfb22d368deec3f0793 Correct test_env.rb path for adding branch
+  # |/
+  # *   1e292f8fedd741b75372e19097c76d327140c312 Merge branch 'cherry-pick-ce369011' into 'master'
+
+  let_it_be(:merge_commit_sha) { 'ddd0f15ae83993f5cb66a927a28673882e99100b' }
+  let_it_be(:merge_base_sha)   { '1e292f8fedd741b75372e19097c76d327140c312' }
+  let_it_be(:branch_name)      { 'stable' }
+
+  let(:repository) { project.repository }
+  let(:commit) { project.commit }
+  let(:user) { create(:user) }
+
+  before do
+    project.add_maintainer(user)
+
+    repository.add_branch(user, branch_name, merge_base_sha)
+  end
+
+  def cherry_pick(sha, branch_name)
+    commit = project.commit(sha)
+
+    described_class.new(
+      project,
+      user,
+      commit: commit,
+      start_branch: branch_name,
+      branch_name: branch_name
+    ).execute
+  end
+
+  describe '#execute' do
+    shared_examples 'successful cherry-pick' do
+      it 'picks the commit into the branch' do
+        result = cherry_pick(merge_commit_sha, branch_name)
+        expect(result[:status]).to eq(:success), result[:message]
+
+        head = repository.find_branch(branch_name).target
+        expect(head).not_to eq(merge_base_sha)
+      end
+    end
+
+    it_behaves_like 'successful cherry-pick'
+
+    context 'when picking a merge-request' do
+      let!(:merge_request) { create(:merge_request, :simple, :merged, author: user, source_project: project, merge_commit_sha: merge_commit_sha) }
+
+      it_behaves_like 'successful cherry-pick'
+
+      it 'adds a system note' do
+        result = cherry_pick(merge_commit_sha, branch_name)
+
+        mr_notes = find_cherry_pick_notes(merge_request)
+        expect(mr_notes.length).to eq(1)
+        expect(mr_notes[0].commit_id).to eq(result[:result])
+      end
+
+      context 'when :track_mr_picking feature flag is disabled' do
+        before do
+          stub_feature_flags(track_mr_picking: false)
+        end
+
+        it 'does not add system notes' do
+          expect do
+            cherry_pick(merge_commit_sha, branch_name)
+          end.not_to change { Note.count }
+        end
+      end
+    end
+
+    def find_cherry_pick_notes(noteable)
+      noteable
+        .notes
+        .joins(:system_note_metadata)
+        .where(system_note_metadata: { action: 'cherry_pick' })
+    end
+  end
+end

spec/services/deployments/link_merge_requests_service_spec.rb

@@ -5,6 +5,19 @@ require 'spec_helper'
 describe Deployments::LinkMergeRequestsService do
   let(:project) { create(:project, :repository) }
 
+  # *   ddd0f15 Merge branch 'po-fix-test-env-path' into 'master'
+  # |\
+  # | * 2d1db52 Correct test_env.rb path for adding branch
+  # |/
+  # *   1e292f8 Merge branch 'cherry-pick-ce369011' into 'master'
+  # |\
+  # | * c1c67ab Add file with a _flattable_ path
+  # |/
+  # *   7975be0 Merge branch 'rd-add-file-larger-than-1-mb' into 'master'
+  let_it_be(:first_deployment_sha) { '7975be0116940bf2ad4321f79d02a55c5f7779aa' }
+  let_it_be(:mr1_merge_commit_sha) { '1e292f8fedd741b75372e19097c76d327140c312' }
+  let_it_be(:mr2_merge_commit_sha) { 'ddd0f15ae83993f5cb66a927a28673882e99100b' }
+
   describe '#execute' do
     context 'when the deployment is for a review environment' do
       it 'does nothing' do
@@ -25,7 +38,7 @@ describe Deployments::LinkMergeRequestsService do
           :deployment,
           :success,
           project: project,
-          sha: '7975be0116940bf2ad4321f79d02a55c5f7779aa'
+          sha: first_deployment_sha
         )
 
         deploy2 = create(
@@ -33,17 +46,14 @@ describe Deployments::LinkMergeRequestsService do
           :success,
           project: deploy1.project,
           environment: deploy1.environment,
-          sha: 'ddd0f15ae83993f5cb66a927a28673882e99100b'
+          sha: mr2_merge_commit_sha
         )
 
         service = described_class.new(deploy2)
 
         expect(service)
           .to receive(:link_merge_requests_for_range)
-          .with(
-            '7975be0116940bf2ad4321f79d02a55c5f7779aa',
-            'ddd0f15ae83993f5cb66a927a28673882e99100b'
-          )
+          .with(first_deployment_sha, mr2_merge_commit_sha)
 
         service.execute
       end
@@ -70,7 +80,7 @@ describe Deployments::LinkMergeRequestsService do
       mr1 = create(
         :merge_request,
         :merged,
-        merge_commit_sha: '1e292f8fedd741b75372e19097c76d327140c312',
+        merge_commit_sha: mr1_merge_commit_sha,
         source_project: project,
         target_project: project
       )
@@ -78,18 +88,97 @@ describe Deployments::LinkMergeRequestsService do
       mr2 = create(
         :merge_request,
         :merged,
-        merge_commit_sha: '2d1db523e11e777e49377cfb22d368deec3f0793',
+        merge_commit_sha: mr2_merge_commit_sha,
         source_project: project,
         target_project: project
       )
 
       described_class.new(deploy).link_merge_requests_for_range(
-        '7975be0116940bf2ad4321f79d02a55c5f7779aa',
-        'ddd0f15ae83993f5cb66a927a28673882e99100b'
+        first_deployment_sha,
+        mr2_merge_commit_sha
       )
 
       expect(deploy.merge_requests).to include(mr1, mr2)
     end
+
+    it 'links picked merge requests' do
+      environment = create(:environment, project: project)
+      deploy =
+        create(:deployment, :success, project: project, environment: environment)
+
+      picked_mr = create(
+        :merge_request,
+        :merged,
+        merge_commit_sha: '123abc',
+        source_project: project,
+        target_project: project
+      )
+
+      mr1 = create(
+        :merge_request,
+        :merged,
+        merge_commit_sha: mr1_merge_commit_sha,
+        source_project: project,
+        target_project: project
+      )
+
+      # mr1 includes c1c67abba which is a cherry-pick of the fake picked_mr merge request
+      create(:track_mr_picking_note, noteable: picked_mr, project: project, commit_id: 'c1c67abbaf91f624347bb3ae96eabe3a1b742478')
+
+      described_class.new(deploy).link_merge_requests_for_range(
+        first_deployment_sha,
+        mr1_merge_commit_sha
+      )
+
+      expect(deploy.merge_requests).to include(mr1, picked_mr)
+    end
+
+    context 'when :track_mr_picking feature flag is disabled' do
+      before do
+        stub_feature_flags(track_mr_picking: false)
+      end
+
+      it 'does not link picked merge requests' do
+        environment = create(:environment, project: project)
+        deploy =
+          create(:deployment, :success, project: project, environment: environment)
+
+        picked_mr = create(
+          :merge_request,
+          :merged,
+          merge_commit_sha: '123abc',
+          source_project: project,
+          target_project: project
+        )
+
+        mr1 = create(
+          :merge_request,
+          :merged,
+          merge_commit_sha: mr1_merge_commit_sha,
+          source_project: project,
+          target_project: project
+        )
+
+        # mr1 includes c1c67abba which is a cherry-pick of the fake picked_mr merge request
+        create(:track_mr_picking_note, noteable: picked_mr, project: project, commit_id: 'c1c67abbaf91f624347bb3ae96eabe3a1b742478')
+
+        mr2 = create(
+          :merge_request,
+          :merged,
+          merge_commit_sha: mr2_merge_commit_sha,
+          source_project: project,
+          target_project: project
+        )
+
+        described_class.new(deploy).link_merge_requests_for_range(
+          first_deployment_sha,
+          mr2_merge_commit_sha
+        )
+
+        expect(deploy.merge_requests).to include(mr1, mr2)
+        expect(deploy.merge_requests).not_to include(picked_mr)
+      end
+    end
   end
 
   describe '#link_all_merged_merge_requests' do

spec/services/system_notes/merge_requests_service_spec.rb

@@ -240,4 +240,25 @@ describe ::SystemNotes::MergeRequestsService do
       expect(subject.note).to eq("created merge request #{merge_request.to_reference(project)} to address this issue")
     end
   end
+
+  describe '.picked_into_branch' do
+    let(:branch_name) { 'a-branch' }
+    let(:commit_sha) { project.commit.sha }
+    let(:merge_request) { noteable }
+
+    subject { service.picked_into_branch(branch_name, commit_sha) }
+
+    it_behaves_like 'a system note' do
+      let(:action) { 'cherry_pick' }
+    end
+
+    it "posts the 'picked merge request' system note" do
+      expect(subject.note).to eq("picked this merge request into branch [`#{branch_name}`](/#{project.full_path}/tree/#{branch_name}) with commit #{commit_sha}")
+    end
+
+    it 'links the merge request and the cherry-pick commit' do
+      expect(subject.noteable).to eq(merge_request)
+      expect(subject.commit_id).to eq(commit_sha)
+    end
+  end
 end