Rate limiting with FeathersJS - Concurrent

rate_limiter_hook.js

import { TooManyRequests } from 'feathers-errors'
import { RateLimiter } from 'limiter'
import makeDebug from 'debug'
const debug = makeDebug('debug')

export function rateLimit (options) {
  const limiter = new RateLimiter(options.tokensPerInterval, options.interval)

  return function (hook) {
    if (hook.type !== 'before') {
      throw new Error(`The 'rateLimit' hook should only be used as a 'before' hook.`)
    }
    let rateLimit = true
    if (options.operation && (options.operation !== hook.method)) {
      rateLimit = false
    }
    
    if (rateLimit) {
      debug(limiter.getTokensRemaining() + ' remaining token for rateLimit hook on service')
      if (!limiter.tryRemoveTokens(1)) { // if exceeded
        throw new TooManyRequests('Too many requests in a given amount of time (rate limiting) on service ')
      }
    }
    return hook
  }
}

// When configuring the service
service.hooks({
  before: {
    all: [ rateLimit({ tokensPerInterval: 5, interval: 60 * 1000, method: 'create' }) ] // 5 calls per minute
    create: [ rateLimit({ tokensPerInterval: 5, interval: 60 * 1000 }) ] // Similar as previous
  }
})