2795. 并行执行 Promise 以获取独有的结果

2795. 并行执行 Promise 以获取独有的结果

type FulfilledObj = {
  status: 'fulfilled'
  value: string
}
type RejectedObj = {
  status: 'rejected'
  reason: string
}
type Obj = FulfilledObj | RejectedObj

function promiseAllSettled(functions: Function[]): Promise<Obj[]> {
  return new Promise((reslove) => {
    const result = Array.from({ length: functions.length })
    let endCount = 0

    for (let i = 0; i < functions.length; i++) {
      functions[i]()
        .then((value: string) => (result[i] = { status: 'fulfilled', value }))
        .catch((reason: string) => (result[i] = { status: 'rejected', reason }))
        .finally(() => {
          endCount += 1
          if (endCount === functions.length) {
            reslove(result as Obj[])
          }
        })
    }
  })
}

/**
 * const functions = [
 *    () => new Promise(resolve => setTimeout(() => resolve(15), 100))
 * ]
 * const time = performance.now()
 *
 * const promise = promiseAllSettled(functions);
 *
 * promise.then(res => {
 *     const out = {t: Math.floor(performance.now() - time), values: res}
 *     console.log(out) // {"t":100,"values":[{"status":"fulfilled","value":15}]}
 * })
 */