fix: fire config-update evnt on perspective-viewer

[jkusa]

This PR resolves #1727 by firing the perspective-config-update event on perspective-viewer element.

This was tested manually. Is there a good place to add a test for this behavior?

[texodus]

Thanks for the PR! Looks good!

I've added a documented integration test for this in #1730

[jkusa]

Thanks @texodus!

I actually thought of a small enhancement to this fix:

const viewer = regularTable.closest("perspective-viewer");
viewer?.dispatchEvent(new Event("perspective-config-update"));

It is a little more specific on what it is trying to achieve and resilient to future DOM changes. I can push another PR or you can update it in #1730. Let me know what works best.

[texodus]

I wouldn't worry about it unless it really bothers you 😄

The perspective source is riddled with rigid DOM structure lookups of this sort, sometimes for performance when a known structure is in a tight loop, but often just out of convenience/laziness/"readability". Personally, I prefer integration tests for behavior we want preserved, as opposed to scrutiny of the "robustness" of a particular implementation.

[jkusa]

Sounds good :)

Personally, I prefer integration tests for behavior we want preserved, as opposed to scrutiny of the "robustness" of a particular implementation.

Yes 💯 Thanks for adding the test.