Svelte Playground - "use events” example fails with duplicate declaration

[rojerian]

Describe the bug

Svelte Playground - "use events” example fails with duplicate declaration
This useful looking Svelte Playground example of "use event” handling ... reports the following message:
npm://$/svelte@3.17.3/internal/index.js (1692:13): Identifier "now" has already been declared

Reproduction

https://svelte.dev/playground/dbeabf42636545b3a8dc6ebe84c2d98c?version=3.17.3

Logs

`npm://$/svelte@3.17.3/internal/index.js (1692:13): Identifier "now" has already been declared`

System Info

https://svelte.dev/playground/

Severity

annoyance

[gterras]

I don't know where this playground is from but it looks like community content (from back in the days).

It is bound to a very old version of svelte, if you pass one of the latest svelte4 release it works : playground 4.2.19.

Switching to latest svelte 5 would need some work as event API has since changed, and most probably there are better ways to do the same thing now.

If a maintainer reads this, maybe displaying the Svelte version somewhere in the UI of the REPL, and warning if the version is really old could help solving this kind of problems.

[brunnerh]

The Playground should save the version the code was authored with and for (sveltejs/svelte.dev#862), then a warning can be displayed if the used version does not match that. The warning could also support directly switching the version.

[rojerian]

Hey … Thanks for the updated Playground link … All working just fine. Much appreciated. Ian +61 434 118 163

…

On 12 Jul 2025, at 11:20 pm, gterras ***@***.***> wrote: gterras left a comment (sveltejs/svelte#16348) <#16348 (comment)> I don't know where this playground is from but it looks like community content (from back in the days). It is bound to a very old version of svelte, if you pass one of the latest svelte4 release it works : playground 4.2.19 <https://svelte.dev/playground/dbeabf42636545b3a8dc6ebe84c2d98c?version=4.2.19>. Switching to latest svelte 5 would need some work as event API has since changed, and most probably there are better ways to do the same thing now. If a maintainer reads this, maybe displaying the Svelte version somewhere in the UI of the REPL, and warning if the version is really old could help solving this kind of problems. — Reply to this email directly, view it on GitHub <#16348 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABRWXNAZS7LUERUBBOTYNQ33IEDRXAVCNFSM6AAAAACBLQIQGCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTANRVGM4DQMRSGE>. You are receiving this because you authored the thread.

[rojerian]

Closed with link to updated Playground playground 4.2.19.