From ee5336623e1152e15295c9c3dea7b6f030e0caba Mon Sep 17 00:00:00 2001
From: share <iaminsharing@gmail.com>
Date: Sun, 12 Jan 2020 15:07:07 +0800
Subject: [PATCH] Fix  - do not change status & value when fulfilled / rejected

Refer:
 1. https://promisesaplus.com/#point-14
 2. https://promisesaplus.com/#point-17
---
 dist/src/promise.js | 10 ++++++++++
 src/promise.js      | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/dist/src/promise.js b/dist/src/promise.js
index bf0870b..9f6d807 100644
--- a/dist/src/promise.js
+++ b/dist/src/promise.js
@@ -27,7 +27,13 @@ class Promise {
     executor(this._resolve.bind(this), this._reject.bind(this));
   }
 
+  _hasResolved() {
+    return this._isFulfilled() || this._isRejected();
+  }
+
   _resolve(x) {
+    if (this._hasResolved()) return;
+
     if (x === this) {
       throw new TypeError("Resolving object can not be the same object");
     } else if (x instanceof Promise) {
@@ -58,12 +64,16 @@ class Promise {
   }
 
   _fulfill(result) {
+    if (this._hasResolved()) return;
+
     this._state = State.Fulfilled;
     this._value = result;
     this._handlers.forEach(handler => this._callHandler(handler));
   }
 
   _reject(error) {
+    if (this._hasResolved()) return;
+
     this._state = State.Rejected;
     this._value = error;
     this._handlers.forEach(handler => this._callHandler(handler));
diff --git a/src/promise.js b/src/promise.js
index 774e0c8..0c12fbe 100644
--- a/src/promise.js
+++ b/src/promise.js
@@ -22,7 +22,13 @@ export class Promise {
     executor(this._resolve.bind(this), this._reject.bind(this));
   }
 
+  _hasResolved() {
+    return this._isFulfilled() || this._isRejected()
+  }
+
   _resolve(x) {
+    if (this._hasResolved()) return
+
     if (x === this) {
       throw new TypeError("Resolving object can not be the same object");
     } else if (x instanceof Promise) {
@@ -57,12 +63,16 @@ export class Promise {
   }
 
   _fulfill(result) {
+    if (this._hasResolved()) return
+
     this._state = State.Fulfilled;
     this._value = result;
     this._handlers.forEach(handler => this._callHandler(handler));
   }
 
   _reject(error) {
+    if (this._hasResolved()) return
+
     this._state = State.Rejected;
     this._value = error;
     this._handlers.forEach(handler => this._callHandler(handler));