refactor(voice): address review feedback on WhatsApp Cloud Calling provider methods

config/locales/en.yml

@@ -243,6 +243,7 @@ en:
       deleted: This message was deleted
       whatsapp:
         list_button_label: 'Choose an item'
+        call_permission_request_body: 'We would like to call you regarding your conversation.'
       delivery_status:
         error_code: 'Error code: %{error_code}'
     activity:

enterprise/app/services/enterprise/whatsapp/providers/whatsapp_cloud_service.rb

@@ -15,9 +15,9 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
     call_api('terminate_call', call_action_body(call_id, 'terminate'))
   end
 
-  def send_call_permission_request(to_phone_number, body_text = 'We would like to call you regarding your conversation.')
+  def send_call_permission_request(to_phone_number, body_text = I18n.t('conversations.messages.whatsapp.call_permission_request_body'))
     response = HTTParty.post(
-      "#{phone_id_path}/messages", headers: api_headers, body: permission_request_body(to_phone_number, body_text).to_json
+      "#{phone_id_path}/messages", headers: api_headers, body: permission_request_body(to_phone_number, body_text)
     )
 
     unless response.success?
@@ -30,7 +30,7 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
 
   def initiate_call(to_phone_number, sdp_offer)
     response = HTTParty.post(
-      "#{phone_id_path}/calls", headers: api_headers, body: initiate_call_body(to_phone_number, sdp_offer).to_json
+      "#{phone_id_path}/calls", headers: api_headers, body: initiate_call_body(to_phone_number, sdp_offer)
     )
     process_initiate_call_response(response)
   end
@@ -60,14 +60,14 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
         action: { name: 'call_permission_request' },
         body: { text: body_text }
       }
-    }
+    }.to_json
   end
 
   def initiate_call_body(to_phone_number, sdp_offer)
     {
       messaging_product: 'whatsapp', to: to_phone_number, type: 'audio',
       session: { sdp: sdp_offer, sdp_type: 'offer' }
-    }
+    }.to_json
   end
 
   def process_initiate_call_response(response)
@@ -78,7 +78,7 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
     error_code = parsed.dig('error', 'code')
     error_msg = parsed.dig('error', 'error_user_msg') || 'Failed to initiate call'
 
-    raise Voice::CallErrors::NoCallPermission, error_msg if error_code == 138_006
+    raise Voice::CallErrors::NoCallPermission, error_msg if error_code == Voice::CallErrors::NO_CALL_PERMISSION_CODE
 
     raise Voice::CallErrors::CallFailed, error_msg
   end

enterprise/lib/voice/call_errors.rb

@@ -1,4 +1,9 @@
 module Voice::CallErrors
+  # Meta WhatsApp Cloud Calling error code returned when the contact has not
+  # granted call permission yet. See `initiate_call` in
+  # Enterprise::Whatsapp::Providers::WhatsappCloudService.
+  NO_CALL_PERMISSION_CODE = 138_006
+
   class NoCallPermission < StandardError; end
   class CallFailed < StandardError; end
   class NotRinging < StandardError; end