warningFilter stopped working with Svelte 5.10.0

[forna]

Describe the bug

I have set the below warningFilter option in svelte.config.js.
It works up to svelte@5.9.1, starting with svelte@5.10.0 it has no effect.
See also: https://github.com/sveltejs/vite-plugin-svelte/issues/988

compilerOptions: {
		warningFilter(w){
			return w.message !== 'Unused CSS selector "*"'
		}
	},

Reproduction

I can reproduce it with this svelte component:

<script>
    import {Circle2} from "svelte-loading-spinners"

    // Props
    let {loadSpinner}  = $props()

    // Spinner type
    const spinnerType = "Circle2"

    // Spinner size in pixels
    const size = 70

</script>


{#if loadSpinner}
    {#if spinnerType === "Circle2"}
        <Circle2 size={size} colorOuter="#8A2BE2" colorCenter="#46B4FD" colorInner="#FFD700" durationOuter="2s" durationCenter="1.5s" durationInner="1s" />
    {/if}
{/if}


<style>
    :global {
        .circle, .wrapper {  /* .circle.svelte-1w4sjib .wrapper.svelte-7wj78d */
            position: fixed; /* Use fixed positioning to keep it in the center of the screen */
            top: 50%;
            left: 50%;
            margin-top: var(--margin-top); /* Half of the spinner size */
            margin-left: var(--margin-left); /* Half of the spinner size */
            display: flex;
            justify-content: center;
            align-items: center;
            z-index: 10000; /* Ensure it is above other content */
        }
    }
</style>

Logs

16:57:48 [vite-plugin-svelte] src/lib/components/component/Spinner.svelte:37:1 Unused CSS selector "*"

System Info

svelte@5.10.0

Severity

annoyance

[trueadm]

Looks like #14629 was the likely culprit

[dummdidumm]

The warning filter should filter by code, not by message. The message (which is not subject to versioning) changed (there's a link in a second line now). So do this instead:

compilerOptions: {
		warningFilter(w){
			return w.code !== 'css_unused_selector'
		}
	},

@dominikg I noticed that v-p-s adds a warning filter for its own injected * selector, but it needs to be updated to account for the new Svelte 5 code:

• https://github.com/sveltejs/vite-plugin-svelte/blob/1b302f1f8b43ddde753fac41f1b0b00dc4acb301/packages/vite-plugin-svelte/src/utils/log.js#L185
• https://github.com/sveltejs/vite-plugin-svelte/blob/1b302f1f8b43ddde753fac41f1b0b00dc4acb301/packages/vite-plugin-svelte/src/utils/log.js#L197

[dummdidumm]

Closing since v-p-s was adjusted + see my message about code vs message etc