feat: lock down success and log

Author: DNR500

app/services/subscriptions/pardot_form_handler_submitter.rb

@@ -6,6 +6,9 @@ class PardotFormHandlerSubmitter
 
     REQUEST_TIMEOUT_SECONDS = 10
     OPEN_TIMEOUT_SECONDS = 5
+    SUCCESS_STATUS_CODES = [200, 302].freeze
+    SUCCESS_LOCATION_PATTERNS = ['/success'].freeze
+    ERROR_LOCATION_PATTERNS = ['/error'].freeze
 
     def initialize(endpoint_url:)
       @endpoint_url = endpoint_url
@@ -15,14 +18,12 @@ def call(form_payload:)
       return missing_configuration_result if endpoint_url.blank?
 
       response = faraday.post(endpoint_url, form_payload)
-      return Result.new(success?: true) if response.success?
-
-      Result.new(
-        success?: false,
-        status: :bad_gateway,
-        error_code: 'subscription_provider_rejected',
-        message: 'Subscription provider rejected the request.'
+      Rails.logger.info(
+        "[subscriptions#provider] status=#{response.status} " \
+        "location=#{redirect_location(response)} " \
+        "classification=#{classification_for(response)}"
       )
+      classify_response(response)
     rescue Faraday::Error
       # Sentry.capture_exception(e)
       Result.new(
@@ -53,5 +54,55 @@ def missing_configuration_result
         message: 'Subscription provider endpoint is not configured.'
       )
     end
+
+    def classify_response(response)
+      return reject_result unless SUCCESS_STATUS_CODES.include?(response.status)
+      return Result.new(success?: true) if response.status == 200
+      return reject_result if redirect_to_error_location?(response)
+      return Result.new(success?: true) if redirect_to_success_location?(response)
+
+      ambiguous_result
+    end
+
+    def reject_result
+      Result.new(
+        success?: false,
+        status: :bad_gateway,
+        error_code: 'subscription_provider_rejected',
+        message: 'Subscription provider rejected the request.'
+      )
+    end
+
+    def ambiguous_result
+      Result.new(
+        success?: false,
+        status: :bad_gateway,
+        error_code: 'subscription_provider_ambiguous',
+        message: 'Subscription provider response was ambiguous.'
+      )
+    end
+
+    def redirect_to_success_location?(response)
+      location = redirect_location(response)
+      SUCCESS_LOCATION_PATTERNS.any? { |pattern| location.include?(pattern) }
+    end
+
+    def redirect_to_error_location?(response)
+      location = redirect_location(response)
+      ERROR_LOCATION_PATTERNS.any? { |pattern| location.include?(pattern) }
+    end
+
+    def redirect_location(response)
+      response.headers.fetch('location', '').to_s.downcase
+    end
+
+    def classification_for(response)
+      return 'rejected_status' unless SUCCESS_STATUS_CODES.include?(response.status)
+      return 'accepted_200' if response.status == 200
+      return 'rejected_error_redirect' if redirect_to_error_location?(response)
+      return 'accepted_success_redirect' if redirect_to_success_location?(response)
+
+      'ambiguous_redirect'
+    end
   end
 end

spec/services/subscriptions/pardot_form_handler_submitter_spec.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Subscriptions::PardotFormHandlerSubmitter do
+  let(:endpoint_url) { 'https://example.com/form-handler' }
+  let(:service) { described_class.new(endpoint_url: endpoint_url) }
+  let(:payload) { { 'email' => 'teacher@example.com', 'privacy_policy' => true } }
+
+  describe '#call' do
+    let(:connection) { instance_double(Faraday::Connection) }
+    let(:response) { instance_double(Faraday::Response, status: status, headers: headers, success?: success) }
+    let(:headers) { {} }
+    let(:status) { 200 }
+    let(:success) { true }
+
+    before do
+      allow(Faraday).to receive(:new).and_return(connection)
+      allow(connection).to receive(:post).and_return(response)
+    end
+
+    it 'returns success for a 200 response' do
+      result = service.call(form_payload: payload)
+
+      expect(result.success?).to be(true)
+    end
+
+    it 'returns success for a 302 success redirect location' do
+      allow(response).to receive_messages(status: 302, success?: false, headers: { 'location' => '/subscriptions/success' })
+
+      result = service.call(form_payload: payload)
+
+      expect(result.success?).to be(true)
+    end
+
+    it 'returns rejected for a 302 error redirect location' do
+      allow(response).to receive_messages(status: 302, success?: false, headers: { 'location' => '/subscriptions/error' })
+
+      result = service.call(form_payload: payload)
+
+      aggregate_failures do
+        expect(result.success?).to be(false)
+        expect(result.error_code).to eq('subscription_provider_rejected')
+      end
+    end
+
+    it 'returns ambiguous for an unknown 302 redirect location' do
+      allow(response).to receive_messages(status: 302, success?: false, headers: { 'location' => '/subscriptions/unknown' })
+
+      result = service.call(form_payload: payload)
+
+      aggregate_failures do
+        expect(result.success?).to be(false)
+        expect(result.error_code).to eq('subscription_provider_ambiguous')
+      end
+    end
+  end
+end