Check for existence of parent component first when filtering mutations

[thormeier]

Suppresses an error caused by the parent component being null in some
cases.

Fixes #90.

[calebporzio]

Hey @thormeier - what are the cases where it's null?

[thormeier]

See #90 - I wasn't able to fully understand the interdependence between Choices and Alpine, but I'm almost sure it happens when the mutation target is removed from the DOM before the observer is triggered. That's at least what my observation yielded.

[joedixon]

I should have read through the PRs first, but I just ran into this same problem and raised and issue #110

I get a similar issue when I have the WhatFont Chrome extension enabled.

[ryatkins]

+1 Get this error as well. Running Chrome in Incognito Mode fixes the issue.

[calebporzio]

Thanks @thormeier.

Any chance you can write a test that simulates this behavior? I merged it, but because no test will fail if I roll it back - it could be refactored out in the future and the error could crop back up again.

Thanks.

[thormeier]

@calebporzio Sure thing, will do a follow-up PR on this.

[thormeier]

@calebporzio Added a test here: #126