Error when destructuring variables in slotted `{@const}`

[brandonmcconnell]

Describe the bug

I can reference properties from a store like this in my template code:

$engagementsContext.sortedBy
$engagementsContext.toggleSort
$engagementsContext.sortActionTitle
$engagementsContext.sortIcon
$engagementsContext.sortedByInverse

…but if I first try to destructure those properties using {@const}, I get this error:

ReferenceFrror: sortedBy is not defined at Array.create_after_title_slot (and so on)

** My hunch is this has to do with the `{@const being considered part of the default slot of its parent's component, while I'm technically trying to use its destructured values in another slot.

Addtl referential screenshots

Working code sample (w/o destructuring)	Broken code screenshot (w/ destructuring)	Resulting error

Reproduction

• Basic reproduction: https://svelte.dev/repl/102dbd6fe6bc441180fa59d8fd2e2c03?version=3.59.1
• Attempted workaround: https://svelte.dev/repl/717d0debe4464481aa9280bbbe0d5708?version=3.59.1
• Attempted workaround #​2: https://svelte.dev/repl/ace70bae29574258847f64e4d033bdd0?version=3.59.1
  ☝🏼 this one actually works and appears to confirm my above hunch

Logs

[HMR][Svelte] Failed to rerender <+page>

ReferenceError: sortedBy is not defined
    at Array.create_after_title_slot (https://dev.carevoyance.com:5001/src/routes/app/(:5001/app/field/providers/search)/field/providers/[providerId]/+page.svelte?t=1684125015357:1729:17)
    at create_slot (index.mjs:71:28)
    at fallback_block_2 (MiniDossierSection.svelte:68:53)
    at create_if_block_4 (MiniDossierSection.svelte:68:53)
    at create_if_block_1 (MiniDossierSection.svelte:69:22)
    at create_fragment (MiniDossierSection.svelte:67:19)
    at init (index.mjs:2113:37)
    at new MiniDossierSection (MiniDossierSection.svelte:50:21)
    at createProxiedComponent (svelte-hooks.js?v=ddc96c07:341:9)
    at new ProxyComponent (proxy.js?v=ddc96c07:242:7)

System Info

System:
  OS: macOS 13.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 535.67 MB / 32.00 GB
  Shell: 5.8.1 - /bin/zsh
Binaries:
  Node: 18.14.2 - ~/.nvm/versions/node/v18.14.2/bin/node
  Yarn: 1.22.19 - /opt/homebrew/bin/yarn
  npm: 9.5.0 - ~/.nvm/versions/node/v18.14.2/bin/npm
Browsers:
  Chrome: 113.0.5672.92
  Chrome Canary: 115.0.5771.0
  Firefox: 112.0.2
  Firefox Nightly: 111.0a1
  Safari: 16.2
  Safari Technology Preview: 16.4
npmPackages:
  svelte: ~3.57.0 => 3.57.0

Severity

annoyance

[dummdidumm]

This works as expected - your hunch is right that you're declaring the @const in the default slot scope but then try to use it in the named slot scope, where it's not defined. Therefore closing. Svelte 5 makes this more obvious with using snippets/render tags instead.