A brief discussion on Axios's solution to remove duplicate requests

// axios.js
const pending = new Map()
/**
 * Add request * @param {Object} config
 **/
const addPending = (config) => {
  const url = [
    config.method,
    config.url,
    qs.stringify(config.data)
  ].join('&')
  if (pending.has(url)) { // If there is a current request in pending, cancel the subsequent request config.cancelToken = new axios.CancelToken(cancel => cancel(`Duplicate requests are actively intercepted: ${url}`))
  } else { // If the current request does not exist in pending, add it config.cancelToken = config.cancelToken || new axios.CancelToken(cancel => {
      pending.set(url, cancel)
    })
  }
}
/**
 * Remove request * @param {Object} config
 */
const removePending = (config) => {
  const url = [
    config.method,
    config.url.replace(config.baseURL, ''), // The response url will add the domain name, which needs to be removed to be consistent with the request URL qs.stringify(JSON.parse(config.data)) // Need to be consistent with the request parameter structure, the request is an object, and the response is a string].join('&')
  if (pending.has(url)) { // If the current request identifier exists in pending, cancel the current request and remove pending.delete(url)
  }
}

/* axios global request parameter settings, request interceptor*/
axios.interceptors.request.use(
  config => {
    addPending(config) // Add the current request to pending return config
  },
  error => {
    return Promise.reject(error)
  }
)
// Response interceptor is exception handling axios.interceptors.response.use(
  response => {
    removePending(response.config) // After the request is completed, remove the return response of this request
  },
  err => {
    if (err && err.config) {
      removePending(err.config) // After the request is completed, remove this request}
    return Promise.resolve(err.response)
  }
)

// axios.js
/**
 * Clear pending requests (called when routing redirects)
 */
export const clearPending = () => {
  for (const [url, cancel] of pending) {
    cancel(url)
  }
  pending.clear()
}

// router.js
router.beforeEach((to, from, next) => {
  // Route jump, clear all requests clearPending()
  })