so-55937835-self-referencing-record

controllers.application.js

import Ember from 'ember';
import { inject as service } from '@ember/service';

export default Ember.Controller.extend({
  store: service(),
  
  init() {
    this._super(...arguments);
 
    let post = this.store.push({
      data: {
        type: 'post',
        id: '1',
        relationships: {
          self: {
            data: {
              type: 'post',
              id: '1'
            }
          }
        }
      }
    });
    console.log(post.id);
    console.log(post.get('self.id'));
  }
});

models.post.js

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

export default Model.extend({
  self: belongsTo('post', { inverse: null })
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}