many to many problem

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

controllers.users.user.js

import Ember from 'ember';

export default Ember.Controller.extend({
  draft: Ember.inject.service(),
  addresses: Ember.computed.mapBy('model.addresses', 'address'),
  actions:{
  	delete(address){
      const id = this.get('model.id');
      const draft = this.get('draft.records');
      if(!this.get(`draft.records.${this.get('model.id')}`)){
      	draft[id] = [];
      }
      address.then(record => {
        record.get('user').then(relationship => {
          draft[id].pushObject({
            modelName: 'user-to-address',
            model:relationship
          });
          this.get('model.addresses').removeObject(relationship);
          relationship.deleteRecord();        
        });
        draft[id].pushObject({
            modelName: 'address',
            model:record
          });
        record.deleteRecord();
      
      });
    },
    undo(){
      const id = this.get('model.id');
      const draft = this.get('draft.records');
    	draft[id].forEach(obj => {
        obj.model.rollbackAttributes();
        if(obj.modelName === 'user-to-address'){
        	this.get('model.addresses').pushObject(obj.model);
        }      	
      });
      this.set(`draft.records.${id}`,[]);
    }
  }
});

mirage.config.js

export default function() {
  this.get('/users', (schema) => {
    return { 
      data: [
        {id:"1", type: "user", attributes: { name: "User 1"}},
        {id:"2", type: "user", attributes: { name: "User 2"}}
      ]
   	};
  });
  this.get('/users/:id',(schema) => {
  	return {
      data: {
        id: "1",
      	type:"user",
        attributes: {	name: "User 1" },
        relationships:{	addresses: { data: [{id:"1", type:"user-to-address"}] } }
      },
      included: [
        {
        	id: "1",
        	type: "user-to-address",
        	attributes: { user_id: "1", address_id:"1" },
          relationships: { 
          	user:{ data: {id:"1", type:"user"} },
            address: { data: {id:"1", type: "address"} }
          }
        },
        {
        	id: "1",
        	type: "address",
        	attributes: { street: "Street 1" },
        	relationships: {
        		user: { data: {id: "1", type: "user-to-address" }}
        	}
        }
      ]
    };
  });
};

mirage.factories.address.js

import Mirage from 'ember-cli-mirage';

export default Mirage.Factory.extend({
  street: function(i) {
    return 'street ' + i
  }
});

mirage.factories.user.js

import Mirage from 'ember-cli-mirage';

export default Mirage.Factory.extend({
  name: function(i) {
    return 'User ' + i
  }
});

mirage.scenarios.default.js

export default function(server) {
  
  window.server = server;
  
  // added this line because global wasn't created otherwise.
  server.createList('user', 10);
  server.createList('address', 10);
}

models.address.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  user: belongsTo('user-to-address'),
  street: attr('string')
});

models.user-to-address.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  address: belongsTo('address'),
  user: belongsTo('user'),
  userId: attr('string'),
  addressId: attr('string')
});

models.user.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  addresses: hasMany('user-to-address'),
  name: attr('string')
});

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('users', function(){
  	this.route('user', {path:':id'});
  });
});

export default Router;

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  beforeModel(){
  	/*const store = this.get('store');
    let user = store.createRecord('user',{
      id: '1',
      name: 'User 1'
    });
    let address = store.createRecord('address',{
    	id: '1',
      street: 'street 1'
    });
    let relationship = store.createRecord('user-to-address',{
    	userId: '1',
      addressId: '1'
    });
    user.get('addresses').pushObject(relationship);
    address.set('user', relationship);
    relationship.set('user',user);
    relationship.set('address',address);*/
  }
});

routes.users.js

import Ember from 'ember';

export default Ember.Route.extend({
  model(){
  	return this.get('store').findAll('user');
  }
});

routes.users.user.js

import Ember from 'ember';

export default Ember.Route.extend({
  draft: Ember.inject.service(),
   model(params){
     const draft = this.get(`draft.records${params.id}`);
     if(!draft || draft.length === 0){
     		return this.get('store').findRecord('user', params.id);
     }
     return this.get('store').peekRecord('user', params.id);  	
  }
});

services.draft.js

import Ember from 'ember';

export default Ember.Service.extend({
  records:[]
});

templates.application.hbs

{{outlet}}

templates.index.hbs

{{#link-to "users"}}users{{/link-to}}

templates.users.hbs

{{outlet}}

templates.users.index.hbs

<h4>Users</h4>
{{#each model as |user|}}
	{{#link-to "users.user" user.id}}{{user.name}}<br>{{/link-to}}
{{/each}}

templates.users.user.hbs

{{#link-to "users" tagName="button"}}back{{/link-to}}
<button onclick={{action 'undo'}}>undo</button>
<h4>{{model.name}}</h4>
<h6>addresses</h6>
{{#each addresses as |address|}}
	{{address.street}}<button onclick={{action 'delete' address}}>x</button><br>
{{/each}}

twiddle.json

{
  "version": "0.10.6",
  "ENV": {
    "ember-cli-mirage": {
      "enabled": true,
      "directory": "app/mirage"
    }
  },
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {
    "ember-cli-mirage": "latest"
  }
}