防抖函数 debounce promise版本debouncePromise

普通函数版

/**
 * 函数防抖
 * @param fn
 * @param ms
 * @returns
 */
export const debounce = (fn: Function, ms = 300) => {
  let timeoutId: ReturnType<typeof setTimeout>
  return function (this: any, ...args: any[]) {
    clearTimeout(timeoutId)
    timeoutId = setTimeout(() => {
      fn.apply(this, args)
    }, ms)
  }
}

如果用普通的 debounce 去防抖 promise 类型的异步函数，是获取不到返回值的。此时需要使用 Promise 版的防抖函数

Promise 版

/**
 * 防抖Promise
 * @param fn
 * @param delay
 * @returns
 */
export function debouncePromise<T = any>(fn: (...arg0: any[]) => Promise<T>, delay = 300) {
  let pendingPromise: ReturnType<typeof setTimeout>

  return function (...args: any[]) {
    if (pendingPromise) {
      clearTimeout(pendingPromise)
    }

    return new Promise((resolve, reject) => {
      pendingPromise = setTimeout(() => {
        fn(...args)
          .then(resolve)
          .catch(reject)
      }, delay)
    })
  }
}