add service to create procedure archive

spec/services/procedure_archive_service_spec.rb

@@ -0,0 +1,63 @@
+describe ProcedureArchiveService do
+  describe '#create_archive' do
+    let(:procedure) { create(:procedure, :published) }
+    let(:instructeur) { create(:instructeur) }
+    let(:service) { ProcedureArchiveService.new(procedure) }
+    let(:year) { 2020 }
+    let(:month) { 3 }
+    let(:date_month) { Date.strptime("#{year}-#{month}", "%Y-%m") }
+
+    before do
+      create_dossier_for_month(year, month)
+      create_dossier_for_month(2020, month)
+    end
+
+    after { Timecop.return }
+
+    context 'for a specific month' do
+      let(:year) { 2021 }
+      let(:mailer) { double('mailer', deliver_later: true) }
+
+      it 'creates a monthly archive' do
+        expect(InstructeurMailer).to receive(:send_archive).and_return(mailer)
+
+        service.create_archive(instructeur, 'monthly', date_month)
+
+        archive = Archive.last
+        archive.file.open do |f|
+          files = ZipTricks::FileReader.read_zip_structure(io: f)
+          expect(files.size).to be 2
+          expect(files.first.filename).to include("export")
+          expect(files.last.filename).to include("attestation")
+        end
+        expect(archive.content_type).to eq 'monthly'
+        expect(archive.file.attached?).to be_truthy
+      end
+    end
+
+    context 'for all months' do
+      let(:mailer) { double('mailer', deliver_later: true) }
+
+      it 'creates a everything archive' do
+        expect(InstructeurMailer).to receive(:send_archive).and_return(mailer)
+
+        service.create_archive(instructeur, 'everything')
+
+        archive = Archive.last
+        archive.file.open do |f|
+          files = ZipTricks::FileReader.read_zip_structure(io: f)
+          expect(files.size).to be 4
+        end
+        expect(archive.content_type).to eq 'everything'
+        expect(archive.file.attached?).to be_truthy
+      end
+    end
+  end
+
+  private
+
+  def create_dossier_for_month(year, month)
+    Timecop.freeze(Time.zone.local(year, month, 5))
+    create(:dossier, :accepte, :with_attestation, procedure: procedure)
+  end
+end