`SPA`: Fails to detect some URL changes when using `MutationObserver`

[nexushoratio]

Unclear if this is an issue with LIT, Scroller, or some other library.

[nexushoratio]

Observation:

 Error: Tried to work with destroyed scroller sandbox eval code:11711:15
    get item moz-extension://49f22fbc-996c-4669-a1f1-61e7f02f0028/ LinkedIn Tool.user.js#1:11711
    #onClick moz-extension://49f22fbc-996c-4669-a1f1-61e7f02f0028/ LinkedIn Tool.user.js#1:12087

This appears to only happen when enableAlertUnknownProfileSections = true.

Though the failure still happens when disabled. Still, may be a clue.

[nexushoratio]

Viewing the image changes the URL, which happens to deactivate the Profile page.

Afterwards, it looks like things may not unwind properly and leaves the keyboard service disabled.

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It appears that SPA is catching the first URL update, but not the second (when it changes back to the profile URL).

[nexushoratio]

It appears that, at least under FF+VM, after dismissing the background image, the URL is updated after the mutation records are processed. And there is no direct way to detect that.

One hack is to wait 1 second and check again.

[nexushoratio]

Two other options:

Modern browsers (2026) directly support the Navigation API which is directly intended to support this (effectively implementing SPA's URL monitoring stuff). (See #358.)

For older browsers, a quick and dirty test using addEventListener('popstate', ...), fired at least once. Needs more testing.