+lastMessage getter in Chat

index.js

@@ -68,6 +68,7 @@ const upload  = require('multer')({ dest: uploadPath })
             _id: ID
             createdAt: String
             lastModified: String
+            lastMessage: Message
             owner: User
 
             title: String

models.js

@@ -174,6 +174,11 @@ module.exports = async (dbName='graphql-chat') => {
             constructor(...params){
                 super(...params)
                 this.members  = Savable.arrize(this.members)
+                this.messages  = Savable.arrize(this.messages)
+            }
+
+            get lastMessage(){
+                return this.messages[this.messages.length -1]
             }
 
             async save(...params){
@@ -205,7 +210,7 @@ module.exports = async (dbName='graphql-chat') => {
             }
 
             static get guestRelations(){
-                return ['messages']
+                return ['messages', 'members']
             }
         }
         SlicedSavable.addClass(Chat)