setupOnerror is running twice in Octane-3.15

When manually asserting an error in a component, setupOnerror is running twice, the first time err.message is the expected error, and the second time I’m receiving Cannot read property 'firstNode' of null.

Steps to reproduce:

ember new my-app
cd my-app

ember g component my-component -gc

my-component.js

import Component from '@glimmer/component';
import { assert } from '@ember/debug';


export default class MyComponentComponent extends Component {
  constructor() {
    super(...arguments);
    assert('test');
  }
}

my-component-test.js

import { module, test } from 'qunit';
import { setupRenderingTest } from 'ember-qunit';
import { render, setupOnerror } from '@ember/test-helpers';
import { hbs } from 'ember-cli-htmlbars';

module('Integration | Component | my-component', function(hooks) {
  setupRenderingTest(hooks);

  test('it does not render', async function(assert) {
    setupOnerror(function(err) {
      assert.equal(err.message, 'Assertion Failed: test');
    });
    await render(hbs`<MyComponent />`);
  });
});

The output from the above test is slightly different than my production output:

I also tested this in the LTS version and it did not occur, it simply ran once with the expected err.message.

My apologies if this is user error.

[rwjblue]

FWIW, fixes for this are incoming. Main upstream fix (and explanation) in https://github.com/glimmerjs/glimmer-vm/pull/1073, but we are working to get those glimmer-vm changes landed in Ember releases now. Likely to be fixed for 3.16 and 3.18+.

[svsalvador]

Hi,

I have the same issue in the project I am working right now. Triaging the error I have found that activating the optional feature application-template-wrapper the issue disappears (you must remove the edition: octane in the package.json to be able to do that).

It can be reproduced in the same repo that @ELepolt has shared: https://github.com/ELepolt/test-helpers-example.

I hope it helps.

Regards.