@const clashes with animate

[janosh]

Describe the bug

Very cool that {@const} is out now! Thanks again to @tanhauhau in #6413! 👍

There's a problem using it together with animate. The following snippet raises

An element that uses the animate directive must be the sole child of a keyed each block

<script>
  import { flip } from 'svelte/animate'
  const indices = [...Array(10).keys()]
</script>

  {#each indices as idx (idx)}
    {@const idxp1 = idx + 1}
    <li animate:flip>
      {idxp1}
    </li>
  {/each}

Reproduction

REPL

Logs

No response

System Info

Irrelevant

Severity

blocking an upgrade

[ghostdevv]

Seems that this issue is caused because when the const tags are stripped from the children nodes of the each block, it leaves behind a text node of tabs and line breaks, when you inline everything to remove the line breaks it compiles correctly {#each indices as idx (idx)}{@const idxp1 = idx + 1}<li animate:flip>

[gtm-nayan]

Possibly related #5477 and #5415

[bluwy]

Also probably related: #3999

[ghostdevv]

This is fixed now @janosh and can be closed

[janosh]

Thanks!