Validate that correct template for the year is used for sales (with headers)

app/services/bulk_upload/sales/validator.rb

@@ -5,6 +5,7 @@ class BulkUpload::Sales::Validator
 
   validate :validate_file_not_empty
   validate :validate_max_columns
+  validate :validate_correct_template
 
   def initialize(bulk_upload:, path:)
     @bulk_upload = bulk_upload
@@ -133,6 +134,12 @@ private
     errors.add(:base, :over_max_column_count) if column_count > csv_parser.class::MAX_COLUMNS
   end
 
+  def validate_correct_template
+    return if halt_validations?
+
+    errors.add(:base, :wrong_template) unless csv_parser.correct_template_for_year?
+  end
+
   def halt_validations!
     @halt_validations = true
   end

app/services/bulk_upload/sales/year2022/csv_parser.rb

@@ -43,6 +43,10 @@ class BulkUpload::Sales::Year2022::CsvParser
     cols[headers.find_index(field) + col_offset]
   end
 
+  def correct_template_for_year?
+    true
+  end
+
 private
 
   def headers

app/services/bulk_upload/sales/year2023/csv_parser.rb

@@ -46,6 +46,10 @@ class BulkUpload::Sales::Year2023::CsvParser
     cols[field_numbers.find_index(field) + col_offset]
   end
 
+  def correct_template_for_year?
+    !with_headers? || (with_headers? && has_field_in_header?(135))
+  end
+
 private
 
   def default_field_numbers
@@ -87,4 +91,8 @@ private
 
     @normalised_string
   end
+
+  def has_field_in_header?(field)
+    rows[rows.find_index { |row| row[0].match(/field number/i) }].any? { |cell| cell&.match?(/#{field}/i) }
+  end
 end

config/locales/en.yml

@@ -55,6 +55,7 @@ en:
             base:
               wrong_field_numbers_count: "Incorrect number of fields, please ensure you have used the correct template"
               over_max_column_count: "Too many columns, please ensure you have used the correct template"
+              wrong_template: "Incorrect fields, please ensure you have used the correct template"
         forms/bulk_upload_lettings/year:
           attributes:
             year:

spec/services/bulk_upload/sales/validator_spec.rb

@@ -27,7 +27,49 @@ RSpec.describe BulkUpload::Sales::Validator do
       end
     end
 
-    context "when incorrect headers"
+    context "when trying to upload 2022 data for 2023 bulk upload" do
+      let(:bulk_upload) { create(:bulk_upload, user:, year: 2023) }
+
+      context "with a valid csv" do
+        let(:path) { file_fixture("2022_23_sales_bulk_upload.csv") }
+
+        it "is not valid" do
+          expect(validator).not_to be_valid
+        end
+      end
+
+      context "with unix line endings" do
+        let(:fixture_path) { file_fixture("2022_23_sales_bulk_upload.csv") }
+        let(:file) { Tempfile.new }
+        let(:path) { file.path }
+
+        before do
+          string = File.read(fixture_path)
+          string.gsub!("\r\n", "\n")
+          file.write(string)
+          file.rewind
+        end
+
+        it "is not valid" do
+          expect(validator).not_to be_valid
+        end
+      end
+
+      context "without headers" do
+        let(:log) { build(:sales_log, :completed) }
+        let(:file) { Tempfile.new }
+        let(:path) { file.path }
+
+        before do
+          file.write(BulkUpload::SalesLogToCsv.new(log:, line_ending: "\r\n", col_offset: 0).to_2022_csv_row)
+          file.close
+        end
+
+        xit "is not valid" do
+          expect(validator).not_to be_valid
+        end
+      end
+    end
   end
 
   describe "#call" do