Axios request queue-like that limits number of requests at any given time

axios.js

import axios from 'axios'

const MAX_REQUESTS_COUNT = 5
const INTERVAL_MS = 10
let PENDING_REQUESTS = 0

// create new axios instance
const api = axios.create({})

/**
 * Axios Request Interceptor
 */
api.interceptors.request.use(function (config) {
	return new Promise((resolve, reject) => {
		let interval = setInterval(() => {
			if (PENDING_REQUESTS < MAX_REQUESTS_COUNT) {
				PENDING_REQUESTS++
				clearInterval(interval)
				resolve(config)
			} 
		}, INTERVAL_MS)
	})
})

/**
 * Axios Response Interceptor
 */
api.interceptors.response.use(function (response) {
	PENDING_REQUESTS = Math.max(0, PENDING_REQUESTS - 1)
	return Promise.resolve(response)
}, function (error) {
	PENDING_REQUESTS = Math.max(0, PENDING_REQUESTS - 1)
	return Promise.reject(error)
})

export default api