Add CsvReportService

Author: lfdebrux

app/services/reports/csv_report_service.rb

@@ -0,0 +1,38 @@
+class Reports::CsvReportService
+  delegate :csv, to: :@csv_service
+
+  def initialize(records)
+    record_type = detect_record_type(records)
+    @csv_service = csv_service_class(record_type).new(records)
+  end
+
+private
+
+  class NilCsvService
+    def initialize(_records); end
+
+    def csv
+      ""
+    end
+  end
+
+  def csv_service_class(record_type)
+    return NilCsvService if record_type.nil?
+
+    "Reports::#{record_type.capitalize}CsvReportService".constantize
+  end
+
+  def detect_record_type(records)
+    return if records.blank?
+
+    type = records.first.fetch("type", "form")
+
+    if type == "form"
+      :forms
+    elsif type == "question_page"
+      :questions
+    else
+      raise "type of records '#{type}' is not one of 'forms', 'question_page'" unless type
+    end
+  end
+end

spec/services/reports/csv_report_service_spec.rb

@@ -0,0 +1,34 @@
+require "rails_helper"
+
+RSpec.describe Reports::CsvReportService do
+  subject(:csv_report_service) do
+    described_class.new(records)
+  end
+
+  describe "#csv" do
+    context "when records is an empty list" do
+      let(:records) { [] }
+
+      it "returns an empty string" do
+        expect(csv_report_service.csv).to eq ""
+      end
+    end
+
+    context "when records is a list of form documents" do
+      let(:records) { JSON.parse(file_fixture("form_documents_response.json").read) }
+
+      it "returns a CSV of forms" do
+        expect(csv_report_service.csv).to eq Reports::FormsCsvReportService.new(records).csv
+      end
+    end
+
+    context "when records is a list of question page documents" do
+      let(:records) { Reports::FeatureReportService.new(form_documents).questions }
+      let(:form_documents) { JSON.parse(file_fixture("form_documents_response.json").read) }
+
+      it "returns a CSV of questions" do
+        expect(csv_report_service.csv).to eq Reports::QuestionsCsvReportService.new(records).csv
+      end
+    end
+  end
+end