test: live query teardown

[elliott-with-the-longest-name-on-github]

closes #

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[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from 20bf6d1:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/20bf6d1d7e82d3f9b071507fa986b264df2f10fd

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16849

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-16849-svelte.vercel.app/

[Nic-Polumeyv]

Restores the request-abort teardown from #16790. Without it, a platform that aborts the request without cancelling the response stream leaves the keep-alive timer enqueueing into an unread buffer forever, and a generator that throws AbortError on disconnect routes a 500 through handleError because open is still true.

Suggested change

	return new Response(
	event.request.signal.addEventListener('abort', () => teardown(true), { once: true });
	return new Response(

Can push a test for the abort path if you take this.

[elliott-with-the-longest-name-on-github]

Huh. I don't know if I'm specifically against this. But should we treat the platform aborting the request without closing the response stream as a bug? That seems like something the platform should definitely be doing.