Function update_pre

packages/svelte/src/internal/client/reactivity/sources.js:315–321

(source, d = 1)

 * @returns {T}
 */
export function update_pre(source, d = 1) {
	var value = get(source);

	// @ts-expect-error
	// eslint-disable-next-line no-useless-assignment -- `++`/`--` used for return value, not side effect on `value`
	return set(source, d === 1 ? ++value : --value);
}

/**
 * Silently (without using `get`) increment a source