Bug: Cannot set property isTrusted of #<Event> [canary]

[mydea]

On latest canary, I get the error:

 TypeError: Cannot set property isTrusted of #<Event> which has only a getter
                at Function.assign (<anonymous>)
                at assign (http://localhost:7357/assets/vendor.js:38987:19)
                at buildBasicEvent (http://localhost:7357/assets/test-support.js:4449:27)
                at fireEvent (http://localhost:7357/assets/test-support.js:4429:15)
                at http://localhost:7357/assets/test-support.js:4271:30

When running tests.

I would suspect this is because on latest canary assign from @ember/polyfills just re-exports Object.assign and this implementation somehow breaks here:

ember-test-helpers/addon-test-support/@ember/test-helpers/dom/fire-event.ts

Line 137 in e55740d

assign(event, options);

I will look into it to see if I can find the issue.

[mydea]

Ok, this is actually a bug in ember, I opened a PR with a fix here: emberjs/ember.js#19692

[rwjblue]

Thanks @mydea!