Sebastian "Sebbie" Silbermann

Thanks for the feedback. We're waiting on a new release of `aria-query` for this. Though I strongly advise against using `level` for treeitems since you'd have to explicitly declare these...

Not sure anymore why this was an issue. But we definitely would need to add support for computing implicit `level` of a `treeitem`

> The reason I think it may be related to MutationObserver is that if I comment [this line](https://github.com/testing-library/dom-testing-library/blob/master/src/wait-for.js?rgh-link-date=2021-01-24T03%3A07%3A31Z#L102) (and any references to observer) then the leaking stops. Could you include...

Facing the same issue with karma. Though I wouldn't narrow it by container. That breaks down once you're UI library supports portals and you can actually have rendered element in...

> Is there no way to specify where portals should be rendered? Or do they always render in the body tag? That's not really relevant here. You shouldn't change the...

Started the effort in https://github.com/testing-library/dom-testing-library/compare/master...eps1lon:feat/pretty-dom-noise. Though it seems like `pretty-format` does not allow to return "nothing". By returning an empty string the spacing is appended (a newline in our case)...

Could you provide a repro that we can test in jsdom and a real browser. We need to verify this doesn't pollute actual browser tests and why this fix can't...

Yeah, I'm not comfortable with monkey patching incomplete environments. This can become super confusing if other libraries don't do that. Why does a polyfill like https://codesandbox.io/s/jsdom-polyfill-transitionevent-bgfz1 doesn't work for you?

> I definitely get that monkey patching this isn't really ideal, but is it worth doing (like [`DataTransfer`](https://github.com/testing-library/dom-testing-library/blob/v7.29.1/src/events.js?rgh-link-date=2021-01-05T22%3A19%3A14Z#L65-L90)) until jsdom supports `window.TransitionEvent`? I consider monkey-patching `DataTransfer` a mistake as well....

If you're confident that you can manually verify the checks ByRole provides then I suggest switching to other queries. ByRole considers the a11y tree, styles and the `accname` spec. These...