Svelte 5: `#each` index used as key causes error

[brunnerh]

Describe the bug

Presumably because the key function only gets passed the item.
Works in v4 so probably shouldn't cause errors in v5, even if it doesn't really do anything.

(Found by Thiagolino8 on Discord.)

Reproduction

{#each [1] as item, i (i)}
	{item}
{/each}

REPL

Logs

No response

System Info

REPL

Severity

annoyance

[trueadm]

Isn't this the same as an indexed array? Why key it at all?

[brunnerh]

I know, it's redundant.
But also a bit more explicit.
In any case, I only reported the issue 🤷

[AgarwalPragy]

This is not fixed.

1. REPL gives the error Cannot have duplicate keys in a keyed each: Keys at index 0 and 1 with value '2' are duplicates
2. For some reason, it still gives me ReferenceError: i is not defined when I run it locally

[brunnerh]

This is a dev mode only issue. The production build is exactly the same (the implemented fix turns it into an indexed each).

This is currently still falsely added in dev mode:

$.validate_each_keys(() => [1, 2, 3], (item) => {
  return $.get(i);
});

[trueadm]

Fixed in #9641.