Force webgl context removal in Context.prototype.destroy

[ethanchristensen01]

Description

Try to force webgl context loss in Context.prototype.destroy so resources can be cleared when the CesiumWidget/Viewer are destroyed.

Issue number and link

#11533 (https://github.com/CesiumGS/cesium/issues/11533)

Testing plan

With this sandcastle below, click "test button" to open a dialog with a cesium viewer inside, and click the "x" button to close it and destroy the viewer. Repeat this process 16 times.

Before, this would have crashed Cesium (specifically on Chrome, I think).

https://sandcastle.cesium.com/#c=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

Author checklist

• [x] I have submitted a Contributor License Agreement
• [x] I have added my name to CONTRIBUTORS.md
• [ ] I have updated CHANGES.md with a short summary of my change
• [ ] I have added or updated unit tests to ensure consistent code coverage
• [ ] I have updated the inline documentation, and included code examples where relevant
• [x] I have performed a self-review of my code

[github-actions[bot]]

Thank you for the pull request, @ethanchristensen01!

:white_check_mark: We can confirm we have a CLA on file for you.

[javagl]

As mentioned in the issue, it looks like this change ~"serves its purpose", and I don't see too much potential for any "negative side-effects" (What could be a "negative side effect" of destroying something, except for that thing being destroyed...?)

When trying it out with the sandcastles in the issue, I wondered whether this can be sensibly covered with unit tests. Could it, at least in theory, be possible to do some setTimeout-trickery to create (and destroy) 17 (!) viewers in quick sequence? Is it necessary to add some delay between creation and destruction? I haven't tried that yet, just wondering...

EDIT: The failing test is only linting. npm run prettier should fix that.

[ethanchristensen01]

Running prettier on my machine changes hundreds of files. On the file modified here, it removes all trailing commas among other things. Is there some configuration for prettier that isn't currently kept in the repo?

[javagl]

I just ran it locally on this branch. There are some changes that I cannot explain (and they already have been merged into main via https://github.com/CesiumGS/cesium/pull/12558/commits/194f9f3a70404413b5b5669ce62fc6b18ce3a540 - no idea where these changes are coming from - maybe @jjhembd knows?). But apart from that, the changes should really be about newlines in the file that was modified here:

[ethanchristensen01]

Ah, that explains why I couldn't see any changes. I'll fix that in about 16 hours probably.

[jjhembd]

@javagl the commit https://github.com/CesiumGS/cesium/commit/194f9f3a70404413b5b5669ce62fc6b18ce3a540 was just aligning https://github.com/CesiumGS/cesium/pull/12558 with main. As you can see from the overall file diff from that PR, those newlines from https://github.com/CesiumGS/cesium/commit/194f9f3a70404413b5b5669ce62fc6b18ce3a540 were in CHANGES.md on the main branch prior to the PR.

I think the actual source is the prettier update in https://github.com/CesiumGS/cesium/pull/12698 (4 days ago). Make sure you have the latest version of prettier installed locally.