Change JSON generator to use language

The JSON generator used to take submission_locale as an argument, and
always include it in the JSON.

Now, only submissions for forms with Welsh will have language set
to en or cy.

This means all current forms won't include a language field unless they
have a Welsh translation added. When the JSON is generated the language
field will be set to nil and the field won't be included.

The argument name has been changed to language as it's more direct and
shows what's being set in the JSON.

Author: thomasiles

app/lib/json_submission_generator.rb

@@ -1,13 +1,17 @@
 class JsonSubmissionGenerator
-  def self.generate_submission(form:, all_steps:, submission_reference:, timestamp:, is_s3_submission:, submission_locale:)
+  def self.generate_submission(form:, all_steps:, submission_reference:, timestamp:, is_s3_submission:, language:)
     submission = {
       "$schema" => "#{Settings.forms_product_page.base_url}/json-submissions/v1/schema",
       form_name: form.name,
       submission_reference:,
       submitted_at: timestamp.getutc.iso8601(3),
-      language: submission_locale,
       answers: all_steps.flat_map { |step| step.show_answer_in_json(is_s3_submission) },
     }
+
+    if language.present?
+      submission[:language] = language
+    end
+
     JSON.pretty_generate(submission)
   end
 end

spec/lib/json_submission_generator_spec.rb

@@ -14,13 +14,13 @@
   let(:selection_step) { build :step, page: build(:page, :with_selections_settings), question: selection_question }
   let(:all_steps) { [text_step, name_step, file_step, address_step, selection_step] }
   let(:submission_reference) { Faker::Alphanumeric.alphanumeric(number: 8).upcase }
-  let(:submission_locale) { :en }
+  let(:language) { nil }
   let(:timestamp) do
     Time.use_zone("London") { Time.zone.local(2022, 9, 14, 8, 0, 0) }
   end
 
   describe ".generate_submission" do
-    subject(:json_submission) { described_class.generate_submission(form:, all_steps:, submission_reference:, timestamp:, is_s3_submission:, submission_locale:) }
+    subject(:json_submission) { described_class.generate_submission(form:, all_steps:, submission_reference:, timestamp:, is_s3_submission:, language:) }
 
     let(:parsed_json) { JSON.parse(json_submission) }
 
@@ -57,7 +57,6 @@
           "form_name" => form.name,
           "submission_reference" => submission_reference,
           "submitted_at" => "2022-09-14T07:00:00.000Z",
-          "language" => "en",
           "answers" => [
             {
               "question_id" => text_step.page.id,
@@ -110,7 +109,6 @@
             "form_name" => form.name,
             "submission_reference" => submission_reference,
             "submitted_at" => "2022-09-14T07:00:00.000Z",
-            "language" => "en",
             "answers" => [
               {
                 "question_id" => repeatable_step.page.id,
@@ -129,6 +127,16 @@
           })
         end
       end
+
+      context "when the language is not nil'" do
+        let(:language) { :cy }
+
+        it "generates the submission JSON with the language field" do
+          expect(parsed_json).to include(
+            "language" => "cy",
+          )
+        end
+      end
     end
 
     context "when the submission is being sent to an S3 bucket" do