Adds service for duplicating a work version.

refs #2674

app/services/new_version_service.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+# Duplicates a version, creating new related objects rather than point at objects for a past version.
+# This is like NewVersionParameter, but it works on objects instead of parameters.
+class NewVersionService
+  # @param [WorkVersion] old_version
+  # @return [WorkVersion] the new version
+  def self.dup(old_version, increment_version: false, save: false, version_description: nil, state: nil)
+    new(old_version).dup(increment_version:, save:, version_description:, state:)
+  end
+
+  def initialize(old_version)
+    @old_version = old_version
+    # Dup does not copy associations.
+    @new_version = old_version.dup
+  end
+
+  def dup(increment_version: false, save: false, version_description: nil, state: nil)
+    dup_attached_files
+    associations_to_filter.each do |relation|
+      dup_relation(relation)
+    end
+
+    new_version.version = old_version.version + 1 if increment_version
+    new_version.version_description = version_description if version_description
+    new_version.state = state if state
+    perform_save if save
+
+    new_version
+  end
+
+  private
+
+  attr_reader :old_version, :new_version
+
+  def dup_attached_files
+    old_version.attached_files.each do |existing_attached_file|
+      new_version.attached_files << dup_attached_file(existing_attached_file)
+    end
+  end
+
+  def dup_attached_file(existing_attached_file)
+    new_attached_file = existing_attached_file.dup
+    new_attached_file.file.attach(existing_attached_file.file.blob.signed_id)
+    new_attached_file
+  end
+
+  def dup_relation(relation)
+    old_version.public_send(relation).each do |existing_relation|
+      new_relation = existing_relation.dup
+      new_version.public_send(relation) << new_relation
+    end
+  end
+
+  def associations_to_filter
+    WorkVersion.aggregate_associations - [:attached_files]
+  end
+
+  def perform_save
+    work = old_version.work
+    work.transaction do
+      new_version.save!
+      work.update!(head_id: new_version.id)
+    end
+  end
+end

spec/services/new_version_service_spec.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe NewVersionService do
+  let(:new_version) do
+    described_class.dup(existing_version, increment_version: true, save: true, version_description: 'A dup',
+                                          state: :version_draft)
+  end
+
+  let(:existing_version) { create(:work_version_with_work_and_collection) }
+
+  let(:attached_file) { create(:attached_file, :with_file) }
+
+  before do
+    existing_version.update(attached_files: [attached_file])
+  end
+
+  it 'duplicates the version' do
+    expect(new_version).to be_a WorkVersion
+    expect(new_version.persisted?).to be true
+    expect(new_version.version).to be 2
+    expect(new_version.version_description).to eq 'A dup'
+    expect(new_version.version_draft?).to be true
+    existing_version.reload
+    expect(new_version.title).to eq existing_version.title
+    expect(new_version.work).to eq existing_version.work
+    expect(existing_version.work.head).to eq new_version
+    expect(new_version.attached_files.count).to eq existing_version.attached_files.count
+    expect(new_version.attached_files.first.label).to eq existing_version.attached_files.first.label
+    expect(new_version.attached_files.first.blob.checksum).to eq existing_version.attached_files.first.blob.checksum
+    expect(new_version.keywords.count).to eq existing_version.keywords.count
+    expect(new_version.keywords.first.label).to eq existing_version.keywords.first.label
+    expect(new_version.authors.count).to eq existing_version.authors.count
+  end
+end