fix: @debug does not work with proxied-state

[adiguba]

Fix #13687

The console.log() generated by @debug receive the proxied state, which causes two bugs :

• It displays the proxy instead of the object himself.
• And so this breaks reactivity as object is not read.

This simple fix simply call $.snapshot() on all the values of {@debug} in order to print correctly the proxied states.

This adds an unnecessary call when the variable is not a proxy-state, but I don't think this is problematic for a debugging tool.

Note : I don't know if this requires a test (and I wouldn't know how to write it)

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[trueadm]

I think we also want to untrack it otherwise it will fire for every change within, which is now how debug tags work.

[adiguba]

I think we also want to untrack it otherwise it will fire for every change within, which is now how debug tags work.

I'm not used to @debug, but the docs say that it's fire on every change :

https://svelte.dev/docs/special-tags#debug
The {@debug ...} tag offers an alternative to console.log(...). It logs the values of specific variables whenever they change, and pauses code execution if you have devtools open.

[trueadm]

I'm not used to @debug, but the docs say that it's fire on every change :

Not for deep state though, @debug isn't designed to do that, $inspect is meant to do that.

[adiguba]

On Svelte 4 or in non-runes mode, @debug work for deep state :

Example : https://svelte-5-preview.vercel.app/#H4sIAAAAAAAAClWO3QrCMAyFXyXkSlH8ua3r0OdwXrguk-JsS5sKUvrurhtDvErOSb6TJOz1QAHFNaG5vwgFXpzDLfLHFRHeNDCNOtjoVXGqoLx2XDem4YEYlI2GyYOENPcCDpBPjan2v01TtZHZGrBGDVo9ZVqtQdYLvJsqbCQc8xSczh218bHMc_EmMAhIf1Auh-bwGsY_X7bTvaYOBftI-Za_OtkbkuIAAAA=

I never used @debug and $inspect() seem a better solution for me.
But as long as @debug is not removed I think it should be responsive to any changes.

[trueadm]

What I mean is that we probably want to untrack in legacy mode, and in runes mode we don't need the untrack. Otherwise this might cause unexpected things happening in legacy components.

I updated the PR and added a test :)