Fix admin invoices CSV output

app/models/invoice.rb

@@ -117,6 +117,23 @@ class Invoice < ApplicationRecord
     e_invoice_sent_at.present?
   end
 
+  def as_csv_row
+    [
+      number,
+      buyer,
+      cancelled? ? I18n.t(:cancelled) : due_date,
+      receipt_date_status,
+      issue_date,
+      total,
+      currency,
+      seller_name
+    ]
+  end
+
+  def self.csv_header
+    ['Number', 'Buyer', 'Due Date', 'Receipt Date', 'Issue Date', 'Total', 'Currency', 'Seller Name'].freeze
+  end
+
   def self.create_from_transaction!(transaction)
     registrar_user = Registrar.find_by(reference_no: transaction.parsed_ref_number)
     return unless registrar_user
@@ -128,6 +145,16 @@ class Invoice < ApplicationRecord
 
   private
 
+  def receipt_date_status
+    if paid?
+      receipt_date
+    elsif cancelled?
+      I18n.t(:cancelled)
+    else
+      I18n.t(:unpaid)
+    end
+  end
+
   def apply_default_buyer_vat_no
     self.buyer_vat_no = buyer.vat_no
   end

app/services/csv_generator.rb

@@ -12,6 +12,6 @@ class CsvGenerator
   private
 
   def self.custom_csv(class_name)
-    [Version::DomainVersion, Version::ContactVersion, Domain, Contact, Invoice].include?(class_name)
+    [Version::DomainVersion, Version::ContactVersion, Domain, Contact, Invoice, Account].include?(class_name)
   end
 end

test/fixtures/files/invoices.csv

@@ -0,0 +1,3 @@
+Number,Buyer,Due Date,Receipt Date,Issue Date,Total,Currency,Seller Name
+2,Best Names,2010-07-06,Unpaid,2010-07-05,16.5,EUR,Seller Ltd
+1,Best Names,2010-07-06,2010-07-05,2010-07-05,16.5,EUR,Seller Ltd

test/system/admin_area/invoices_test.rb

@@ -40,4 +40,14 @@ class AdminAreaInvoicesTest < ApplicationSystemTestCase
     assert_current_path admin_invoice_path(@invoice)
     assert_text 'Invoice has been sent'
   end
+
+  def test_download_invoices_list_as_csv
+    travel_to Time.zone.parse('2010-07-05 10:30')
+
+    visit admin_invoices_url
+    click_link('CSV')
+
+    assert_equal "attachment; filename=\"invoices_#{Time.zone.now.to_formatted_s(:number)}.csv\"; filename*=UTF-8''invoices_#{Time.zone.now.to_formatted_s(:number)}.csv", response_headers['Content-Disposition']
+    assert_equal file_fixture('invoices.csv').read, page.body
+  end
 end