lastMessage object does not return reactions and I explain why this is a problem

[rafaelks]

Description:

Here's a lastMessage with reactions coming from the rooms API endpoint:

{
      "t" : "d",
      "_updatedAt" : "2018-09-28T13:42:42.424Z",
      "_id" : "9dDK3Bfpq2j9TLRDthFcuvjJeHfNjeYAqQ",
      "lastMessage" : {
        "mentions" : [ ],
        "sandstormSessionId" : null,
        "u" : {
          "_id" : "9dDK3Bfpq2j9TLRDt",
          "name" : "Fullname Of The User",
          "username" : "rafaelks.test.2"
        },
        "_id" : "joFSJiaR7madn07H1t",
        "ts" : "2018-09-28T13:42:42.142Z",
        "rid" : "9dDK3Bfpq2j9TLRDthFcuvjJeHfNjeYAqQ",
        "unread" : true,
        "msg" : "Teste 2",
        "_updatedAt" : "2018-09-28T13:42:42.153Z",
        "channels" : [ ]
      }
}

Here's the message object, when coming from the list of messages:

{
        "mentions" : [],
        "u" : {
          "_id" : "9dDK3Bfpq2j9TLRDt",
          "name" : "Fullname Of The User",
          "username" : "rafaelks.test.2"
        },
        "_id" : "joFSJiaR7madn07H1t",
        "reactions" : {
          ":umbrella2:" : {
            "usernames" : [
              "rafaelks.test.2"
            ]
          }
        },
        "ts" : {
          "$date" : 1538142162142
        },
        "rid" : "9dDK3Bfpq2j9TLRDthFcuvjJeHfNjeYAqQ",
        "msg" : "Teste 2",
        "_updatedAt" : {
          "$date" : 1538145553439
        },
        "channels" : [ ]
}

The problem is that not having reactions in lastMessage would not be a big deal if when we request the message from the messages API it returned reactions: [] for an empty list. Today it doesn't return the property.

What's the problem? The only way we know today if the reactions list is empty or not is because the property is not being returned (both APIs). Problem is that if we don't have that on the lastMessage, it will remove the reactions from the database and then when the user opens the list of message the reactions are gone.

My question for you guys is: can we apply any of this proposals in order to get this consistent?

1. Always return reactions in a message object;
2. Always return reactions in the list of messages, even in the list of reactions is empty.