[#2180] High-level PJ to champ PJ migration service

app/services/piece_justificative_to_champ_piece_jointe_migration_service.rb

@@ -0,0 +1,93 @@
+class PieceJustificativeToChampPieceJointeMigrationService
+  def initialize(**params)
+    params.each do |key, value|
+      instance_variable_set("@#{key}", value)
+    end
+  end
+
+  def ensure_correct_storage_configuration!
+    storage_service.ensure_openstack_copy_possible!(PieceJustificativeUploader)
+  end
+
+  def convert_procedure_pjs_to_champ_pjs(procedure)
+    types_de_champ_pj = PiecesJustificativesService.types_pj_as_types_de_champ(procedure)
+    populate_champs_pjs!(procedure, types_de_champ_pj)
+
+    # Only destroy the old types PJ once everything has been safely migrated to
+    # champs PJs. Destroying the types PJ will cascade and destroy the PJs,
+    # and delete the linked objects from remote storage. This means that no other
+    # cleanup action is required.
+    procedure.types_de_piece_justificative.destroy_all
+  end
+
+  def storage_service
+    @storage_service ||= CarrierwaveActiveStorageMigrationService.new
+  end
+
+  def populate_champs_pjs!(procedure, types_de_champ_pj)
+    procedure.types_de_champ += types_de_champ_pj
+
+    # Unscope to make sure all dossiers are migrated, even the soft-deleted ones
+    procedure.dossiers.unscope(where: :hidden_at).find_each do |dossier|
+      champs_pj = types_de_champ_pj.map(&:build_champ)
+      dossier.champs += champs_pj
+
+      champs_pj.each do |champ|
+        type_pj_id = champ.type_de_champ.old_pj&.fetch('stable_id', nil)
+        pj = dossier.retrieve_last_piece_justificative_by_type(type_pj_id)
+        if pj.present?
+          convert_pj_to_champ!(pj, champ)
+        end
+      end
+    end
+  rescue
+    # If anything goes wrong, we roll back the migration by destroying the newly created
+    # types de champ, champs blobs and attachments.
+    types_de_champ_pj.each do |type_champ|
+      type_champ.champ.each { |c| c.piece_justificative_file.purge }
+      type_champ.destroy
+    end
+
+    # Reraise the exception to abort the migration.
+    raise
+  end
+
+  def convert_pj_to_champ!(pj, champ)
+    blob = make_blob(pj)
+
+    # Upload the file before creating the attachment to make sure MIME type
+    # identification doesn’t fail.
+    storage_service.copy_from_carrierwave_to_active_storage!(pj.content.path, blob)
+    attachment = storage_service.make_attachment(champ, 'piece_justificative_file', blob)
+
+    # By reloading, we force ActiveStorage to look at the attachment again, and see
+    # that one exists now. We do this so that, if we need to roll back and destroy the champ,
+    # the blob, the attachment and the actual file on OpenStack also get deleted.
+    champ.reload
+  rescue
+    # Destroy partially attached object that the more general rescue in `populate_champs_pjs!`
+    # might not be able to handle.
+
+    if blob&.key.present?
+      begin
+        storage_service.delete_from_active_storage!(blob)
+      rescue => e
+        # The cleanup attempt failed, perhaps because the object had not been
+        # successfully copied to the Active Storage bucket yet.
+        # Continue trying to clean up the rest anyway.
+        pp e
+      end
+    end
+
+    blob&.destroy
+    attachment&.destroy
+    champ.reload
+
+    # Reraise the exception to abort the migration.
+    raise
+  end
+
+  def make_blob(pj)
+    storage_service.make_blob(pj.content, pj.updated_at.iso8601, filename: pj.original_filename)
+  end
+end

spec/services/piece_justificative_to_champ_piece_jointe_migration_service_spec.rb

@@ -0,0 +1,170 @@
+require 'spec_helper'
+
+describe PieceJustificativeToChampPieceJointeMigrationService do
+  let(:service) { PieceJustificativeToChampPieceJointeMigrationService.new(storage_service: storage_service) }
+  let(:storage_service) { CarrierwaveActiveStorageMigrationService.new }
+  let(:pj_uploader) { class_double(PieceJustificativeUploader) }
+  let(:pj_service) { class_double(PiecesJustificativesService) }
+
+  let(:procedure) { create(:procedure, types_de_piece_justificative: types_pj) }
+  let(:types_pj) { [create(:type_de_piece_justificative)] }
+
+  let!(:dossier) do
+    create(
+      :dossier,
+      procedure: procedure,
+      pieces_justificatives: pjs
+    )
+  end
+
+  let(:pjs) { [] }
+
+  def make_pjs
+    types_pj.map do |tpj|
+      create(:piece_justificative, :contrat, type_de_piece_justificative: tpj)
+    end
+  end
+
+  def expect_storage_service_to_convert_object
+    expect(storage_service).to receive(:make_blob)
+    expect(storage_service).to receive(:copy_from_carrierwave_to_active_storage!)
+    expect(storage_service).to receive(:make_attachment)
+  end
+
+  context 'when conversion succeeds' do
+    context 'for the procedure' do
+      it 'types de champ are created for the "pièces jointes" header and for each PJ' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { procedure.types_de_champ.count }
+          .by(types_pj.count + 1)
+      end
+
+      it 'the old types de pj are removed' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { procedure.types_de_piece_justificative.count }
+          .to(0)
+      end
+    end
+
+    context 'for the dossier' do
+      let(:pjs) { make_pjs }
+
+      before { expect_storage_service_to_convert_object }
+
+      it 'champs are created for the "pièces jointes" header and for each PJ' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { dossier.champs.count }
+          .by(types_pj.count + 1)
+      end
+
+      it 'the old pjs are removed' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { dossier.pieces_justificatives.count }
+          .to(0)
+      end
+    end
+
+    context 'when the dossier is soft-deleted it still gets converted' do
+      let(:pjs) { make_pjs }
+
+      let!(:dossier) do
+        create(
+          :dossier,
+          procedure: procedure,
+          pieces_justificatives: pjs,
+          hidden_at: Time.zone.now
+        )
+      end
+
+      before { expect_storage_service_to_convert_object }
+
+      it 'champs are created for the "pièces jointes" header and for each PJ' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { dossier.champs.count }
+          .by(types_pj.count + 1)
+      end
+
+      it 'the old pjs are removed' do
+        expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+          .to change { dossier.pieces_justificatives.count }
+          .to(0)
+      end
+    end
+
+    context 'when there are several pjs for one type' do
+      let(:pjs) { make_pjs + make_pjs }
+
+      it 'only converts the most recent PJ for each type PJ' do
+        expect(storage_service).to receive(:make_blob).exactly(types_pj.count)
+        expect(storage_service).to receive(:copy_from_carrierwave_to_active_storage!).exactly(types_pj.count)
+        expect(storage_service).to receive(:make_attachment).exactly(types_pj.count)
+
+        service.convert_procedure_pjs_to_champ_pjs(procedure)
+      end
+    end
+  end
+
+  context 'cleanup when conversion fails' do
+    let(:pjs) { make_pjs }
+
+    let!(:failing_dossier) do
+      create(
+        :dossier,
+        procedure: procedure,
+        pieces_justificatives: make_pjs
+      )
+    end
+
+    before do
+      allow(storage_service).to receive(:checksum).and_return('cafe')
+      allow(storage_service).to receive(:fix_content_type)
+
+      expect(storage_service).to receive(:copy_from_carrierwave_to_active_storage!)
+      expect(storage_service).to receive(:copy_from_carrierwave_to_active_storage!)
+        .and_raise('LOL no!')
+
+      expect(storage_service).to receive(:delete_from_active_storage!)
+    end
+
+    def try_convert(procedure)
+      service.convert_procedure_pjs_to_champ_pjs(procedure)
+    rescue => e
+      e
+    end
+
+    it 'passes on the exception' do
+      expect { service.convert_procedure_pjs_to_champ_pjs(procedure) }
+        .to raise_error('LOL no!')
+    end
+
+    it 'does not create champs' do
+      expect { try_convert(procedure) }
+        .not_to change { dossier.champs.count }
+    end
+
+    it 'does not remove any old pjs' do
+      expect { try_convert(procedure) }
+        .not_to change { dossier.pieces_justificatives.count }
+    end
+
+    it 'does not creates types de champ' do
+      expect { try_convert(procedure) }
+        .not_to change { procedure.types_de_champ.count }
+    end
+
+    it 'does not remove old types de pj' do
+      expect { try_convert(procedure) }
+        .not_to change { procedure.types_de_piece_justificative.count }
+    end
+
+    it 'does not leave stale blobs behind' do
+      expect { try_convert(procedure) }
+        .not_to change { ActiveStorage::Blob.count }
+    end
+
+    it 'does not leave stale attachments behind' do
+      expect { try_convert(procedure) }
+        .not_to change { ActiveStorage::Attachment.count }
+    end
+  end
+end