Svelte Playground doesn't work in Safari 17 or lower

[kevinrenskers]

The Svelte Playground doesn't work in Safari except for Safari 18. This is a pretty big problem as I rely on the Playground to test components and their CSS in older browsers (using browserstack.com).

This is Safari 12:

Safari 13 and 14:

Safari 15 and 16 and 17: it looks good but it never stops loading the compiler:

Only in Safari 18 does it work as expected:

[dummdidumm]

anything in devtools that gives a hint (I don't have access to Safari)? Like, is this just a missing polyfill?

[kevinrenskers]

Safari 12:

Safari 13:

Safari 14:

Safari 15, 16 and 17:

Promise.withResolvers was added in Safari 17.4 (https://caniuse.com/mdn-javascript_builtins_promise_withresolvers).