@monstermann/fn/dist/promise/limit.js

A utility library for TypeScript.

import { queue } from "./queue.js";

//#region src/promise/limit.ts
/**
* `limit(fn, options)`
*
* Limits the concurrency of function execution.
*
* ```ts
* const limitedFetch = limit(fetch, { concurrency: 3 });
* const limitedFetch2 = limit(fetch, 3); // Shorthand
*
* const results = await Promise.all([
*     // At most 3 fetch calls are executed at any time
*     limitedFetch("/api/1"),
*     limitedFetch("/api/2"),
*     limitedFetch("/api/3"),
*     limitedFetch("/api/4"),
* ]);
*
* // Wait for queue to become idle
*/
function limit(fn, options) {
	const q = queue(options);
	const limited = function(...args) {
		return q.add(() => fn(...args));
	};
	limited.idle = q.idle;
	return limited;
}

//#endregion
export { limit };