New Twiddle

tests.foo-test.js

import { module, test, todo } from "ember-qunit";
import EmberObject from "@ember/object";
import Mixin from "@ember/object/mixin";


module( "simple es6 classes with .extend", {
  before() {
    // Works
    this.A = class A extends EmberObject {
      foo = 1;
    }
    this.B = class B extends this.A {
      foo = 2;
    }
    this.C = class C extends EmberObject.extend({ foo: 3 }) {}
    this.D = class D extends EmberObject.extend( Mixin.create({ foo: 4 }) ) {}

    // Extending native classes with Ember doesn't work in Ember >=3.2, even if
    // https://ember-decorators.github.io/ember-decorators/latest/docs/native-class-basics#extending-native-classes-with-extend-
    // claims that it's working.
    this.E = class E extends this.A.extend({ foo: 5 }) {}
    this.F = class F extends this.A.extend({ foo: 5 }) {
      foo = 6;
    }
    this.G = class G extends this.A.extend( Mixin.create({ foo: 7 }) ) {}
    this.H = class H extends this.A.extend( Mixin.create({ foo: 7 }) ) {
      foo = 8;
    }
  }
});

test( "create", function( assert ) {
  assert.strictEqual( this.A.create().foo, 1, "a.foo === 1" );
  assert.strictEqual( this.B.create().foo, 2, "b.foo === 2" );
  assert.strictEqual( this.C.create().foo, 3, "c.foo === 3" );
  assert.strictEqual( this.D.create().foo, 4, "d.foo === 4" );
  assert.strictEqual( this.E.create().foo, 5, "e.foo === 5" );
  assert.strictEqual( this.F.create().foo, 6, "f.foo === 6" );
  assert.strictEqual( this.G.create().foo, 7, "g.foo === 7" );
  assert.strictEqual( this.H.create().foo, 8, "h.foo === 8" );
});

// optional test, as it's not officially supported
todo( "new", function( assert ) {
  assert.strictEqual( new this.A().foo, 1, "a.foo === 1" );
  assert.strictEqual( new this.B().foo, 2, "b.foo === 2" );
  assert.strictEqual( new this.C().foo, 3, "c.foo === 3" );
  assert.strictEqual( new this.D().foo, 4, "d.foo === 4" );
  assert.strictEqual( new this.E().foo, 5, "e.foo === 5" );
  assert.strictEqual( new this.F().foo, 6, "f.foo === 6" );
  assert.strictEqual( new this.G().foo, 7, "g.foo === 7" );
  assert.strictEqual( new this.H().foo, 8, "h.foo === 8" );
});

tests.test-helper.js

import Application from '../app';
import config from '../config/environment';
import { setApplication } from '@ember/test-helpers';
import { start } from 'ember-qunit';
import { assign } from '@ember/polyfills';

let attributes = assign({ rootElement: '#main' }, config.APP);
setApplication(Application.create(attributes));

start();

twiddle.json

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