computed property array wrapping

controllers.application.js

import Ember from 'ember';
import { computed, set } from '@ember/object';
import { isArray } from '@ember/array';
import { typeOf } from '@ember/utils';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  incidents: null,
  
  allIncidents: computed('incidents', function() {
		const incidents = this.incidents;
    
    if (incidents) {
      return isArray(incidents) ? incidents : [ incidents ];
    } else {
    	return null;
    }
  }),
  
	incidentsType: computed('incidents', function() {
  	return typeOf(this.incidents);
  }),
  
  actions: {
  	setIncidentsArray() {
			set(this, 'incidents', [ {name: 'foo'}, {name: 'bar'} ]);
    },
    
    setIncidentsObject() {
    	set(this, 'incidents', {name: 'bar'});
    },
    
    resetIncidents() {
    	set(this, 'incidents', null);
    }
  }
});

templates.application.hbs

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

Incidents Property Type: {{incidentsType}}
<br>
<button {{action "setIncidentsArray"}}>Set Incidents Array</button>
<button {{action "setIncidentsObject"}}>Set Incidents Object</button>
<button {{action "resetIncidents"}}>Set Incidents Null</button>
<br>
{{#if allIncidents}}
	{{#each allIncidents as |incident|}}
  	<li>{{incident.name}}</li>
  {{/each}}
{{else}}
	Empty Incidents
{{/if}}

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"
  }
}