[4.0.0-beta4] BUG: hx-prompt not working on Unicode input [error: String contains non ISO-8859-1 code point]

[YamiOdymel]

#3828 adds hx-prompt back to HTMX 4 as an extension to fix #3825

I grabbed the extension directly from the pull request, but then I encountered an error with 4.0.0-beta4 if prompt contains Chinese character:

htmx: htmx:error: Failed to execute 'fetch' on 'Window': Failed to read the 'headers' property from 'RequestInit': String contains non ISO-8859-1 code point. TypeError: Failed to execute 'fetch' on 'Window': Failed to read the 'headers' property from 'RequestInit': String contains non ISO-8859-1 code point.
    at #issueRequest (htmx.js:544:42)
    at #handleTriggerEvent (htmx.js:509:37)
    at htmx.js:343:51
    at inner (htmx.js:719:21)
    at spec.handler (htmx.js:769:21)

L544                 let response = await ctx.fetch(ctx.request.action, ctx.request);
L509                 await this.#issueRequest(ctx);
L343                 await this.#handleTriggerEvent(ctx);
L719                 handler(evt);
L769                 timed(evt);

This appears to be the same issue as #3781, but the comment mentioned that it was fixed in 4.0.0-beta3 🤔?

[MichaelWest22]

Yeah this extension would also need to wrap the header setting with encodeURI() just like the id we did earlier.

Not sure if this extension is ideal though as really the prompt text should be added to the parameters and not a header with limited character passing restriction. You can decode the URI encoding maybe but it may not be obvious.

[MichaelWest22]

fix for this is now merged