fix: shouldExcludeFromA11yTree runs in IE11

[briandipalma]

IE11 returns undefined for missing parentElement.

fix: In IE11 when an element lacks parentElement it returns undefined instead of null.

Why: Because otherwise you get these errors

TypeError: Unable to get property 'hidden' of undefined or null reference
	error properties: Object({ number: -2146823281 })
	    at <Jasmine>
	   at shouldExcludeFromA11yTree (eval code:824:5)
	   at Anonymous function (eval code:995:5)
	   at Anonymous function (eval code:28:7)
	   at filter (eval code:11:5)
	   at queryAllByRole (eval code:994:3)

Checklist:

• Documentation added to the
  docs site N/A
• I've prepared a PR for types targetting https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/testing-library__dom N/A
• Tests N/A
• [x ] Ready to be merged
  

[eps1lon]

I couldn't find any documentation for that. Only that parentElement isn't implemented for Node which would explain the undefined value. But this leads to the question why there is a Node passed to this function in the first place.

It might make more sense to throw if this is getting passed a Node since there is no specification for what kind of nodes should be part of the a11y tree. It's only defined for Element.

[eps1lon]

Could you include a reproduction that fails with IE 11? This would help a lot 🙏

[briandipalma]

Yes it seems like it's not implemented on Node Only supported on Element. from https://developer.mozilla.org/en-US/docs/Web/API/Node/parentElement

But the element that failed for us was an SVG and I found this: https://stackoverflow.com/a/36270354/1927079

In Internet Explorer, parentElement is undefined for SVG elements, whereas parentNode is defined.

Do your tests run in IE11?

[eps1lon]

But the element that failed for us was an SVG and I found this:

Interesting. I'll verify that and add it to the MDN docs since SVGElement inherits from Element.

Do your tests run in IE11?

We don't run any tests in browsers and so far browser support hasn't been a priority from what I can tell. I use this library in browser tests though so anytime I do find one I'll try to fix it (#362, #363).

[briandipalma]

I'll try and add a test that covers the failure I see here.

[briandipalma]

Added a test but this would only ever fail in IE11.

[eps1lon]

Could you write the test so that you only use public methods? Then I could verify this with a test suite running in IE 11 (via browserstack) as I'm still not convinced this is the source of the issue.

[briandipalma]

Updated the tests, is this what you were thinking?

[briandipalma]

Is this OK?

[kentcdodds]

This LGTM :) Thanks!

[kentcdodds]

🎉 This PR is included in version 6.5.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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