fix: correct hash routing behavior

[stephenlrandall]

closes #13460 and #13322

As is, Kit doesn't correctly handle some aspects of hash routing. Spurious navigations are triggered when using the back button in the browser, but only for certain kinds of routes and in certain environments (see #13460 for details). This seems to be a consequence of differences in when current.url is modified, which makes the existing check for user edits to the URL error-prone. Instead (and to also fix #13322), the popstate event is used and triggers a simple page reload.

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Preview: https://svelte-dev-git-preview-kit-13492-svelte.vercel.app/

[stephenlrandall]

@eltigerchino Sorry, I needed to recreate this since the original was on the main branch of my fork, so I couldn't open any other PRs.

[dummdidumm]

You say it also closes #13460, which makes me nervous. I don't want us to reload everything when the user navigates via a back button.

[stephenlrandall]

You say it also closes #13460, which makes me nervous. I don't want us to reload everything when the user navigates via a back button.

It doesn't, that code is only triggered -- as far as I can tell -- for non-navigation popstate events.

[stephenlrandall]

@dummdidumm To clarify, the issue in #13460 is the deleted code. It does detect user changes to the URL, but it also triggers incorrectly on certain navigations in the browser. So deleting that code fixes #13460 but leaves the app unresponsive to user changes to the hash. To address that (while also resolving #13322), I added the reload for non-navigation popstate events that are triggered when a user edits the URL.

[stephenlrandall]

@elliott-with-the-longest-name-on-github Mildly confused by the tag here -- what decision(s) would need to be made? The current hash router breaks the expected history stack. Deleting the offending code fixes the problem but leaves the app unresponsive to user URL edits. And while you could try to trigger a navigation where I currently have a page reload, you'd run back into #13322 and inconsistency with the pathname router. Is there something I'm overlooking? I'll admit I'm not overly familiar with the codebase. But I'm certainly not triggering page reloads on forward/back-button navigations, at least as far as I can tell.

[dummdidumm]

dug into this some more - the change is sound. Thank you!