Patching limiter with async getTokens

limiter-get-tokens.js

const {RateLimiter} = require('limiter');

RateLimiter.prototype.getTokens = async function (count) {
    const that = this;
    if (count <= this.tokenBucket.bucketSize) {
        return new Promise((resolve, reject) => {
            this.removeTokens(count, (err, remaining) => {
                if (err) {
                    return reject(err);
                }
                return resolve(count);
            });
        });
    }

    const interval = this.tokenBucket.interval;
    const tokensPerInterval = this.tokenBucket.tokensPerInterval;
    const shapingTimeMs = Math.ceil(count * (interval / tokensPerInterval));
    const numIntervals = shapingTimeMs / interval;
    let consumed = 0;
    let chunk = this.tokenBucket.bucketSize;
    while (consumed < count) {
        chunk = Math.min(chunk, count - consumed);

        consumed += await new Promise((resolve, reject) => {
            that.removeTokens(chunk, (error, remaining) => {
                if (error) {
                    reject(error);
                } else {
                    resolve(chunk);
                }
            });
        });
    }
    return consumed;
};