How to unproxy a $prop?

[leon]

Describe the bug

$props are proxies if I understand it correctly.

If I want to pass along a prop or a field of a prop to another script I would like a way to deproxify it.

I tried using $state.snapshot(prop.field)
but it hangs

Either I'm missing something, or we need a way to unproxify props

Reproduction

https://svelte-5-preview.vercel.app/#H4sIAAAAAAAAE52TTW-cMBCG_8rIjbQgIcj2SJet-nHpLVKPIQcWhsUNeJA9bHaF-O-VbSDZjdJDL9jM2M-88-FR1LJFI9LHUaiiQ5GKb30vIsGX3v6YE7aMIhKGBl1ay86UWvYMbaGOWS7Y5GKfq5xl15Nm-D4wk4JaUwebOPG_scds7LkWGQ7OaiCDO8MFY_BoPTmPfsnZSklhM8O2m2hx9GQkS1IpjHBO4T6CSwr3k3dP0T8xnz_EbD1new16Cr_kapf4fG2OavyERdms8gszbyHwa2wDhg6ym4NWBRfZ6N0TJPtcjYmFTCISHVWylliJlPWAU7S2wN_9jy6onJMEDOqTLDFm4xqjGHVdlAgPc9Y-aTV0B9Qucb8FJ7weVOkOVfSbOuRGqmPwWq-FEcJc5SSBxQumoaGtQBHDAaHXdL4AHf5gyRE09AJMUMvzV3-xJGWoxbilV344N2ghc0PDsYFf0Mlj46DFoUXLGQzOwxMbVfSmIXZm5aMaHuo6su2BitA4SS-kn1eyjc6wXF0rk91Cb6XNVxfhtwB3avKdsHkAvJbfd_VBU29s8QDATUcKN_NqWEt1fD-qS4x5Ri3BfeyLGh0KpvQqSgZ3vd0EVpYCWHtL6kcry-cgXIW8abYlxW_SdmGu3sHOz7N12QnNcjEbhDWRKi08GwM8oeIQsv0SxhniXrv1J9bF0HIQet-qyUWc9qPTYUsy7ZIl4D5X7x_O0_QXQzN848cEAAA=

Logs

No response

System Info

Not applicable

Severity

blocking an upgrade

[brunnerh]

Something weird going on, the snapshot call just gets completely removed if assigning to a variable.

// Input:
function doSomething(position) {
	const snapshotPosition = $state.snapshot(position)
	console.log(snapshotPosition)
	// console.log($state.snapshot(position))
}

// Output:
function doSomething(position) {
	console.log(snapshotPosition);
} // console.log($state.snapshot(position))

(Also note the odd position of the comment outside the function.)

Without variable:

// Input:
function doSomething(position) {
	// const snapshotPosition = $state.snapshot(position)
	// console.log(snapshotPosition)
	console.log($state.snapshot(position))
}

// Output:
function doSomething(position) {
	// const snapshotPosition = $state.snapshot(position)
	// console.log(snapshotPosition)
	console.log($.snapshot(position));
}

REPL

[7nik]

The entire variable declaration with a snapshot's value is missing in the compiled code. REPL
If you separate variable declaration and initialization, it compiles correctly.