From eee04539d853629b8aa97492ec07c3eade8905c4 Mon Sep 17 00:00:00 2001
From: yigencong <yigencong@yahoo.com>
Date: Mon, 8 Apr 2024 18:34:59 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E6=B7=BB=E5=8A=A0=E9=9D=99=E6=80=81?=
 =?UTF-8?q?=E5=87=BD=E6=95=B0reslove=E5=92=8Creject=E4=BB=A5=E5=8F=8Aall?=
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---
 js/手写Promise.js | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/js/手写Promise.js b/js/手写Promise.js
index 98b12d4..bb9e43f 100644
--- a/js/手写Promise.js
+++ b/js/手写Promise.js
@@ -19,12 +19,14 @@ MyPromise.REJECT = 2
 
 
 MyPromise.resolve = function(res) {
+  if(this === MyPromise) return new MyPromise(resolve=>resolve(res)) // 如果是静态调用就返回一个确认的Promise
   if(this.status === MyPromise.REJECT) return // Promise 的状态一旦确定就不能修改
   this.status = MyPromise.FULFILLED
   this.result = res
 }
 
 MyPromise.reject = function(err) {
+  if(this === MyPromise) return new MyPromise((resolve,reject)=>reject(err)) // 如果是静态调用就返回一个拒绝的Promise
   if(this.status === MyPromise.FULFILLED) return // Promise 的状态一旦确定就不能修改
   this.status = MyPromise.REJECT
   this.result = err
@@ -50,3 +52,31 @@ MyPromise.prototype = {
     return this
   }
 }
+
+// 编写Promise.all([...Promies])静态方法
+
+/**
+ * @description 接受一个Promise的迭代对象，当全部的Promise兑现时，返回一个由兑现值组成的迭代对象
+ * 当为空的迭代对象时也会对象一个空的迭代对象 Promise.all([]).then(res=>{console.log(res)}) res = []
+ */
+MyPromise.all = function (ps) {
+  if(typeof ps[Symbol.iterator] !== 'function') throw new Error("传递一个内容为Promise实例的可迭代对象")
+  var n = ps.length
+  var rs = []
+  for(var i = 0; i < n; i++) {
+    (function(i){
+      ps[i].then(res=>{
+        rs[i] = res
+      }, err=>{
+        // all只要出现拒绝，就立马返回第一个拒绝的内容
+        this.status = MyPromise.REJECT;
+        this.result = err
+      })
+    }).call(this, i)
+  }
+  if (this.status === MyPromise.REJECT) return this
+
+  this.status = MyPromise.FULFILLED
+  this.result = rs
+  return this
+}