/** Observe cancellation while awaiting work that cannot itself be cancelled (such as import()). */
export async function awaitWithAbort<T>(operation: Promise<T>, signal?: AbortSignal): Promise<T> {
	if (!signal) return operation;
	let onAbort: () => void = () => {};
	const aborted = new Promise<never>((_resolve, reject) => {
		onAbort = () => reject(new Error("Aborted"));
		signal.addEventListener("abort", onAbort, { once: true });
		if (signal.aborted) onAbort();
	});
	try {
		const result = await Promise.race([operation, aborted]);
		if (signal.aborted) throw new Error("Aborted");
		return result;
	} finally {
		signal.removeEventListener("abort", onAbort);
	}
}