Query Param badness

controllers.a\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { inject as service } from '@ember/service';

export default class extends Controller {
  @service router;
  
  @action
  redirectWithTransitionToRoute() {
    this.transitionToRoute('b');
  }
  
  @action
  redirectWithTransitionTo() {
    this.router.transitionTo('b');
  }
}

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

controllers.b\.js

import Controller from '@ember/controller';

export default class extends Controller {
  queryParams = [ 'foo', 'bar', 'baz' ];

	foo = null;
	bar = '';
	baz = 'not null';
}

router\.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

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

Router.map(function() {
  this.route('a');
  this.route('b');
});

export default Router;

routes.a\.js

import Route from '@ember/routing/route';

export default Route.extend({
  
});

routes.b\.js

import Route from '@ember/routing/route';

export default Route.extend({
});

templates.a\.hbs

<button type="button" data-test-transitionToRoute {{on "click" this.redirectWithTransitionToRoute}}>
  this.transitionToRoute
</button>

<button type="button" data-test-transitionTo {{on "click" this.redirectWithTransitionTo}}>
  this.router.transitionTo
</button>

templates.application\.hbs

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

tests.acceptance.transition-to-query-params-test\.js

import { module, test } from 'qunit';
import { click, visit, currentURL } from '@ember/test-helpers';
import { setupApplicationTest } from 'ember-qunit';

module('transitionToRoute on controller', function(hooks) {
  setupApplicationTest(hooks);

  test('result does not include default values for unspecified query params', async function(assert) {
    await visit('/a');
    await click('button[data-test-transitionToRoute]');

    assert.equal(currentURL(), '/b');
  });
});

module('transitionTo on router service', function(hooks) {
  setupApplicationTest(hooks);

  test('result does not include default values for unspecified query params', async function(assert) {
    await visit('/a');
    await click('button[data-test-transitionTo]');

    assert.equal(currentURL(), '/b');
  });
});

tests.test-helper\.js

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

let attributes = {
  rootElement: '#test-root',
  autoboot: false
};
attributes = assign(attributes, config.APP);

let application = Application.create(attributes);
setApplication(application);

start();

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": true
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}