Callback throttler

bullshit.js

let timeout = null;
let requestCount = 0;
let queue = [];

function schedule(limit) {
  if (!timeout) {
    timeout = setTimeout(() => throttleQueue(limit), 1000)
  }
}

function throttleQueue(limit) {
  timeout = null;
  requestCount = 0;

  while (requestCount < limit) {
    let callback = queue.pop();
    if (callback) {
      schedule(limit)
      callback();
      ++requestCount;
    } else {
      break
    }
  }
}

/**
 * Returns a function that will throttle
 * callbacks to the limit per second
 **/
function throttle(limit) {
  return function(callback) {
    if (requestCount >= limit) {
      schedule(limit)
      queue = [callback, ...queue]
    } else {
      ++requestCount
      callback()
    }

  }
}

// Request will be fired max 2 per second
const request = throttle(2)

request(() => console.log("1"))
request(() => console.log("2"))
request(() => console.log("3"))
request(() => console.log("4"))
request(() => console.log("5"))
request(() => console.log("6"))
request(() => console.log("7"))
request(() => console.log("8"))