[4.0.0-beta6] hx-preload fails to reuse cached GET when hx-get uses relative URLs

[woutergrimme]

Bug report

Using htmx 4.0.0-beta6 with the hx-preload extension.

When preloading a link with a relative hx-get URL, the preload request is made successfully, but the cached response is not reused on click.

Example:

<a
    hx-get="https://domain.com/some/url"
    hx-preload="mouseover timeout:10s">
    Some link
</a>

Steps to reproduce:
Hover the link.
Wait for the preload request to complete.
Click the link.

Expected:
The click should reuse the preloaded response.

Actual:
A second GET request is sent.

Debugging showed:

cached action : https://domain.com/some/url
current action: /some/url

The comparison in hx-preload.js:

elt._htmx.preload.action === ctx.request.action

This fails because the URLs are semantically identical but different strings.

A possible fix (tested locally):

elt._htmx.preload.action === new URL(ctx.request.action, location.href).href

This normalizes the URL before comparison.

Environment:

htmx: 4.0.0-beta6
hx-preload: 4.0.0-beta6
Browser: Chrome/Firefox

[MichaelWest22]

Thanks for finding this. I've pushed up a fix that reuses the core htmx logic to calculate the action url to compare with which seems to be a more reliable fix from my testing. Would be good if you can test yourself with the four-dev branch src/htmx.js version to confirm it fixes your issue.