New Twiddle

tests.foo-test.js

import { module, test, setupTest } from "ember-qunit";
import { default as EmberObject, computed, observer, set } from "@ember/object";
import { addObserver } from "@ember/object/observers";


module( "value observer", function( hooks ) {
	setupTest( hooks );

	hooks.beforeEach(function() {
		// no value observer
		this.owner.register( "obj:a", EmberObject.extend({
			value: "default"
		}) );

		// value observer added on init
		this.owner.register( "obj:b", EmberObject.extend({
			value: "default",
			init() {
				this._super( ...arguments );
				addObserver( this, "value", () => {} );
			}
		}) );

		// observer function
		this.owner.register( "obj:c", EmberObject.extend({
			value: "default",
			_valueObserver: observer( "value", function() {} )
		}) );

		// observer function and computed property
		this.owner.register( "obj:d", EmberObject.extend({
			value: computed( () => "default" ),
			_valueObserver: observer( "value", function() {} )
		}) );
	});

	test( "value", function( assert ) {
		const a = this.owner.lookup( "obj:a" );
		const b = this.owner.lookup( "obj:b" );
		const c = this.owner.lookup( "obj:c" );
		const d = this.owner.lookup( "obj:d" );

		assert.strictEqual( a.value, "default", "a.value === 'default'" );
		assert.strictEqual( b.value, "default", "b.value === 'default'" );
		assert.strictEqual( c.value, "default", "c.value === 'default'" );
		assert.strictEqual( d.value, "default", "d.value === 'default'" );

		set( a, "value", 123 );
		assert.strictEqual( a.value, 123, "a.value === 123" );
		set( b, "value", 123 );
		assert.strictEqual( b.value, 123, "b.value === 123" );
		set( c, "value", 123 );
		assert.strictEqual( c.value, 123, "c.value === 123" );
		set( d, "value", 123 );
		assert.strictEqual( d.value, 123, "d.value === 123" );

		set( a, "value", undefined );
		assert.strictEqual( a.value, undefined, "a.value === undefined" );
		set( b, "value", undefined );
		assert.strictEqual( b.value, undefined, "b.value === undefined" );
		set( c, "value", undefined );
		assert.strictEqual( c.value, undefined, "c.value === undefined" );
		set( d, "value", undefined );
		assert.strictEqual( d.value, undefined, "d.value === undefined" );
	});
});

tests.test-helper.js

import { setResolver } from 'ember-qunit';
import { start } from 'ember-cli-qunit';
import Resolver from '../resolver';
import config from '../config/environment';

setResolver(Resolver.create({
  namespace: {
    modulePrefix: config.modulePrefix,
    podModulePrefix: config.podModulePrefix
  }
}));
start();

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": true
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}