fix Combine service and add specs

app/services/data_exports/combine_parts_service.rb

@@ -10,30 +10,32 @@ def initialize(data_export:)
 
     def call
       result.data_export = data_export
-      data_export.transaction do
-        data_export.completed!
 
-        Tempfile.create([data_export.resource_type, ".#{data_export.format}"]) do |tempfile|
-          tempfile.write(data_export.export_class.headers.join(';'))
+      Tempfile.create([data_export.resource_type, ".#{data_export.format}"]) do |tempfile|
+        tempfile.write(data_export.export_class.headers.join(','))
+        tempfile.write("\n")
 
-          # Note the order here, this is crucial to make sure the data is in the expected order
-          data_export.data_export_parts.order(:index).find_each { |part| tempfile.write(part.csv_lines) }
+        # Note the order here, this is crucial to make sure the data is in the expected order
+        data_export.data_export_parts.order(:index).find_each { |part| tempfile.write(part.csv_lines) }
 
-          tempfile.rewind
+        tempfile.rewind
 
-          data_export.file.attach(
-            io: tempfile,
-            filename: data_export.filename,
-            key: "data_exports/#{data_export.id}.#{format}",
-            content_type: "text/csv"
-          )
-
-          data_export.completed!
-        end
+        data_export.file.attach(
+          io: tempfile,
+          filename: data_export.filename,
+          key: "data_exports/#{data_export.id}.#{data_export.format}",
+          content_type: "text/csv"
+        )
       end
+
+      data_export.completed!
       DataExportMailer.with(data_export:).completed.deliver_later
 
       result
     end
+
+    private
+
+    attr_reader :data_export
   end
 end

spec/services/data_exports/combine_parts_service_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe DataExports::CombinePartsService, type: :service do
+  subject(:result) { described_class.call(data_export:) }
+
+  let(:data_export) { create :data_export, :processing, resource_type: 'invoice_fees' }
+  let(:data_export_part) { create :data_export_part, data_export:, csv_lines: }
+  let(:csv_lines) do
+    <<~CSV
+      292ef60b-9e0c-42e7-9f50-44d5af4162ec,TWI-2B86-170-001,2024-06-06,cc16e6d5-b5e1-4e2c-9ad3-62b3ee4be302,charge,group,group,charge 1 description,group,Converted to EUR,"{:models=>""model_1""}",ff6c279c-9f6c-4962-987e-270936d52310,all_charges,2024-05-08T00:00:00+00:00,2024-06-06T12:48:59+00:00,USD,100.0,10.0,50,10000
+    CSV
+  end
+
+  before do
+    data_export_part
+  end
+
+  describe "#call" do
+    context "when there is only 1 part" do
+      it "adds the correct headers" do
+        expected_csv = <<~CSV
+          invoice_lago_id,invoice_number,invoice_issuing_date,fee_lago_id,fee_item_type,fee_item_code,fee_item_name,fee_item_description,fee_item_invoice_display_name,fee_item_filter_invoice_display_name,fee_item_grouped_by,subscription_external_id,subscription_plan_code,fee_from_date_utc,fee_to_date_utc,fee_amount_currency,fee_units,fee_precise_unit_amount,fee_taxes_amount_cents,fee_total_amount_cents
+          292ef60b-9e0c-42e7-9f50-44d5af4162ec,TWI-2B86-170-001,2024-06-06,cc16e6d5-b5e1-4e2c-9ad3-62b3ee4be302,charge,group,group,charge 1 description,group,Converted to EUR,"{:models=>""model_1""}",ff6c279c-9f6c-4962-987e-270936d52310,all_charges,2024-05-08T00:00:00+00:00,2024-06-06T12:48:59+00:00,USD,100.0,10.0,50,10000
+        CSV
+
+        expect(result).to be_success
+        expect(data_export.file.download).to eq(expected_csv)
+      end
+    end
+
+    context "when there are multiple parts" do
+      let(:data_export_part2) { create :data_export_part, data_export:, csv_lines: csv_lines2, index: 2 }
+      let(:csv_lines2) do
+        <<~CSV
+          392ef60b-9e0c-42e7-9f50-44d5af4162ec,TWI-2B86-170-001,2024-06-06,cc16e6d5-b5e1-4e2c-9ad3-62b3ee4be302,charge,group,group,charge 1 description,group,Converted to EUR,"{:models=>""model_1""}",ff6c279c-9f6c-4962-987e-270936d52310,all_charges,2024-05-08T00:00:00+00:00,2024-06-06T12:48:59+00:00,USD,100.0,10.0,50,10000
+        CSV
+      end
+
+      before { data_export_part2 }
+
+      it "combines the parts into 1 file on the data export" do
+        expected_csv = <<~CSV
+          invoice_lago_id,invoice_number,invoice_issuing_date,fee_lago_id,fee_item_type,fee_item_code,fee_item_name,fee_item_description,fee_item_invoice_display_name,fee_item_filter_invoice_display_name,fee_item_grouped_by,subscription_external_id,subscription_plan_code,fee_from_date_utc,fee_to_date_utc,fee_amount_currency,fee_units,fee_precise_unit_amount,fee_taxes_amount_cents,fee_total_amount_cents
+          292ef60b-9e0c-42e7-9f50-44d5af4162ec,TWI-2B86-170-001,2024-06-06,cc16e6d5-b5e1-4e2c-9ad3-62b3ee4be302,charge,group,group,charge 1 description,group,Converted to EUR,"{:models=>""model_1""}",ff6c279c-9f6c-4962-987e-270936d52310,all_charges,2024-05-08T00:00:00+00:00,2024-06-06T12:48:59+00:00,USD,100.0,10.0,50,10000
+          392ef60b-9e0c-42e7-9f50-44d5af4162ec,TWI-2B86-170-001,2024-06-06,cc16e6d5-b5e1-4e2c-9ad3-62b3ee4be302,charge,group,group,charge 1 description,group,Converted to EUR,"{:models=>""model_1""}",ff6c279c-9f6c-4962-987e-270936d52310,all_charges,2024-05-08T00:00:00+00:00,2024-06-06T12:48:59+00:00,USD,100.0,10.0,50,10000
+        CSV
+
+        expect(result).to be_success
+        expect(data_export.file.download).to eq(expected_csv)
+      end
+    end
+  end
+end

spec/services/data_exports/process_part_service_spec.rb

@@ -60,4 +60,14 @@
       expect { result }.to have_enqueued_job(DataExports::CombinePartsJob).with(data_export_part.data_export)
     end
   end
+
+  context 'when other parts have not been complete' do
+    let(:other_part) { create :data_export_part, data_export:, object_ids: [invoice.id], index: 2 }
+
+    before { other_part }
+
+    it "does not enqueue a job" do
+      expect { result }.not_to have_enqueued_job(DataExports::CombinePartsJob).with(data_export_part.data_export)
+    end
+  end
 end