Generate public url from vite plugin

[Monokai]

I'm writing a simple vite plugin that reads the width and height from a video file and returns an object that contains the width, height and src. This is in the context of a 100% static site generated with SvelteKit.

Everything works perfectly fine a dev environment, but on build, the files are getting written to the assets folder with a hash in their name, like every other asset. My question is how can I generate this hashed filename from within my plugin so the src file contains the right url?

If I understand correctly, I only have the src and id information in my plugin transform callback:

async transform(src, id) {
    //… ?

    const o = `{
        src: "${encodeURI(filePath)}",
        width: ${w},
        height: ${h}
    }`;

    return {
        code: `export default ${o}`
    }
}

But whatever I do, even calculating my own hash via

function getHash(text, length = 8) {
	const h = createHash('sha256').update(text).digest('hex').substring(0, length)

	if (length <= 64) {
		return h;
	}

	return h.padEnd(length, '_')
}

…the output unfortunately isn't the same as the hash contained in the asset filename in the build folder.

Does anyone have any documentation or pointers on how to solve this?