TS/JS Async Lock

lock.ts

/**
 * A TypeScript async lock implemented with promise chaining.
 *
 * Usage:
 *
 *     this._lock.with(async () => {
 *         await doThing1();
 *         await doThing2(a);
 *     });
 */
export class AsyncLock {
    private _queue: Promise<unknown> = Promise.resolve();

    /**
     * Run an async function (the `executor`) within the scope of this lock.
     *
     * All enqueued executors are processed serially.
     */
    public with<T>(executor: () => T | Promise<T>): Promise<T> {
        this._queue = this._enqueue(this._queue, executor);
        return this._queue as Promise<T>;
    }

    /**
     * Await the queue, then await and return the executor.
     */
    private async _enqueue<T>(queue: Promise<unknown>, executor: () => T | Promise<T>): Promise<T> {
        try {
            await queue;
        } catch {
            // Ignored
        }
        return await executor();
    }
}