feat: allow for fine grained invalidation of search params

[paoloricciuti]

This PR basically allow for sveltekit users to have fine grained control over the access to searchParams. This means that if inside a load function i access url.searchParams.get("test") and nothing more that load function will actually only rerun when the test search params changes (so not if the url changes and the search param is the same, not if another search param changes).

There's an issue about this #8403 and i've talked both with Simon and Ben before going with this PR.

Technically this is a breaking change (in case someone was relying on this behavior to invalidate the route by accessing a search param). We could in theory put this behind a settings and eventually do the breaking change in kit 2.0, what do you think?

I've added the tests only for get but in theory there could be tests to check for has, getAll and the fact that every other thing accessed (like size, entries, values) should invalidate the whole url. Let me know if you want me to add also that.

I think it would be useful to update the docs too in this PR, if you think otherwise I'll continue working on this in an HR or so, so stop me now if you want! I added the docs too.

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[paoloricciuti]

Looks good!
One thing I'm not quite sure about: Will this solves #8403 (comment), too? i.e. the URL changes, but since you're only listening to search params the load function should not rerun when the search param does not change. Then again, that's probably wrong in other circumstances, since you may have the same search param on a different page which does mean something different, and as such it should rerun? Then again, if the value does not change, and you only use the value to request data, that's correct anyway? Mhm ...

Yeah this solves that problem too and as you've said if it's dependent only on that searchParam if it's not changing you don't need to rerun the load function.

[paoloricciuti]

@dummdidumm gentle ping that this is technically ready...do it at your own pace since i know there's a lot of stuff going on, just wanted to remind since from outside it seems CI is failing because vercel is not authorized to deploy but all the rest of the stuff is green 😄

[gtm-nayan]

I don't see a reason to pass this into create_client as a param. This could be done using define and that'd reduce the complexity of the config quite a bit on the server side.

[paoloricciuti]

I don't think i've ever heard of define...do you have a link to some resource i can look into?

[gtm-nayan]

https://vitejs.dev/config/shared-options.html#define

[paoloricciuti]

Oh i think now i realized it's from vite...exploring this a bit

[paoloricciuti]

How is the deploying failing now? I just added a couple of letters in the markdown 😄

[dummdidumm]

Sorry the back and forth - we decided to make this part of SvelteKit 2.0 (which we want to start working on very soon), so you can remove the config option again 😅

[paoloricciuti]

Sorry the back and forth - we decided to make this part of SvelteKit 2.0 (which we want to start working on very soon), so you can remove the config option again 😅

No problem I will revert those commits back, just a bit sad because I needed this feature but it's fine as long as sooner or later we can get that 😄

[Rich-Harris]

Thanks — made a few changes in #11258 (couldn't commit directly to this branch) so I'll close this in favour of that