[Stadly]

Closes #547.

Svelte 5 removes whitespace at the start and end of an element's content (migration guide). Since 4.0 the plugin supports only Svelte 5, so a line break after > or before </ can't change what renders. The plugin still hugs those tags to avoid adding that whitespace, which gives this for #547's example:

<span class="highlight"
    ><strong>Some text that is long</strong><small
        >Some more text</small
    ></span
>

With this change it prints:

<span class="highlight">
    <strong>Some text that is long</strong><small>
        Some more text
    </small>
</span>

Whitespace between siblings still renders, so </strong><small> and </span>, stay together as before. Content inside <pre> and <textarea> keeps hugging, and so does htmlWhitespaceSensitivity: "strict".

Two smaller changes make the output match what you'd write by hand. When the source has no whitespace at an edge, the separator is a softline, so <b>Bold</b> stays as it is when it fits instead of becoming <b> Bold </b>. A tag without attributes no longer breaks before its >, so an overflowing line doesn't end in <span with the > alone on the next line.

The README FAQ about hugging described the Svelte 4 behavior, so I rewrote it.

Testing

16 fixtures have new expected output. I compiled the old and the new version of each with svelte/compiler, client and server, and got identical code for every one. Three of them don't compile as whole files (animate: outside a keyed {#each}, <svelte:fragment slot> without a parent), so for those I compiled only the elements that changed.

Two fixtures are new. One holds #547's example and text right after an element. The other covers <pre> and <textarea>, and its output is the same as before this change.

I also ran the plugin over a SvelteKit app with 828 formatted components. It changed only the 27 files that still had the hugged layout, and each of them compiles to the same code as before.