throttle-wait

throttle-wait

Run a function at max once per x milliseconds. Subsequent calls will wait.

• 0 dependencies
• Typescript friendly (can use @Decorators)

Installation

$ npm install throttle-wait

or

$ yarn add throttle-wait

Simple usage

import { throttle } from 'throttle-wait'

function myFn() {
  console.log(new Date())
}

const myFnThrottled = throttle(5 * 1000, myFn) // 5s

// 2020-01-01T00:00:00.114Z
await myFnThrottled()

// 2020-01-01T00:00:05.120Z
await myFnThrottled()

// 2020-01-01T00:00:10.125Z
await myFnThrottled()

Typescript decorator usage

import { Throttle } from 'throttle-wait'

class MyClass {
  @Throttle(5 * 1000) // 5s
  public async myFn() {
    console.log(new Date())
  }
}
const myClass = new MyClass()

// 2020-01-01T00:00:00.114Z
await myClass.myFn()

// 2020-01-01T00:00:05.120Z
await myClass.myFn()

// 2020-01-01T00:00:10.125Z
await myClass.myFn()

IMPORTANT: Make your function async. The decorator will return an async function. This will ensure that the intellisense of your IDE tells you that your function is async.

Options

const myFnThrottled = throttle(throttleTime, myFn, {
  max: 100,
  onThrottle: (next, queue) => {
    console.log(`Throttling, will run in ${next}ms (${queue} in the queue)`)
  },
})

• max (default=100): The maximum number of calls in the queue before throwing an error
• onThrottle: Callback when your function is being throttled

Errors

Throttle backpressure error: Throttle is being called faster than it can run

This means that your function is being called a lot asynchronously. An error is thrown when there are 100 calls in the queue (configurable).

Advance throttling

If you want to ignore subsequent calls, look at lodash throttle function

• https://www.npmjs.com/package/lodash.throttle

If you want to have more throttling control, you can check out these great libs.

• https://github.com/jhurliman/node-rate-limiter
• https://github.com/SGrondin/bottleneck