Cannot get has_many ids sent to API

Ember Data
1

I have been fighting this problem for a couple of days and just can’t figure out what I am doing wrong. I have a HABTM relationship side up in Rails and I have that set up in Ember as well. Anytime I try and add a record to the relationship, I never see any ids sent with the json.

Here is my action:

var self = this,
            player = {},
            game = {};

            self.set('notify','');

            this.set('content',this.get('session.currentUser'));

            if(Ember.isEmpty(this.get('gameId'))){
                game = self.store.createRecord('game');

                game.save()
                    .then(function(){
                        return self.model.save();
                    })
                    .then(function(newPlayer){
                        player = newPlayer;
                        return game.get('players');
                    })
                    .then(function(players){
                        players.pushObject(player);
                        return game.save();
                    })
                    .then(function(){
                        self.transitionToRoute('games.game',game);
                    })
                    .catch(function(err){
                        // TODO Need better error handling here
                        console.log(err);
                        throw err;
                    });

self.model is a Player model. This will send a JSON request body:

{"game":{"token":"g-XxcnOo","state":0,"player_ids":[]}}

This is my serializer that I have set up:

export default DS.ActiveModelSerializer
    .extend(DS.EmbeddedRecordsMixin)
    .extend({
        attrs: {
            createdAt: { serialize: false },
            updatedAt: { serialize: false },
            players: { serialize: 'ids', deserialize: 'ids' },
            owner: { embedded: 'always', serialize: 'id', deserialize: 'id' }
        }
    });

and this is my model:

export default DS.Model.extend({
    token: DS.attr('string'),
    state: DS.attr('number'),
    createdAt: DS.attr('date'),
    updatedAt: DS.attr('date'),
    players: DS.hasMany('player',{ async: true, inverse: 'games' }),
    gameCards: DS.hasMany('gameCard',{ async: true }),
    owner: DS.belongsTo('player',{ async: true, inverse: 'currentGame' })
});

Any help would be really appreciated.

I am using ActiveModelSerializer and Ember-Data 1.0.0-beta10

###Update 1

So I have been playing around with the order that my operations are going through in the action and I now am seeing something odd. If I do not save the game object, just push an object to it, a player will show up, but as soon as I save the game that player is removed.

###Update 2

The only solution I could find was to remove {async: true} and go to embedding all my relationships. This is now working for me. However, it does give me cause for concern if Ember 2.0 is planning on going to {async: true} in the future, not to mention the benefits of lazy loading those relationships to being with.