From a09e802f51baa7f6dac58cbb98f8c6a285f4a487 Mon Sep 17 00:00:00 2001
From: Denis Pushkarev <zloirock@zloirock.ru>
Date: Tue, 27 Apr 2021 16:02:29 +0300
Subject: [PATCH] make `.constructor === Promise` work with polyfilled
 `Promise` for all native promise-based APIs

---
 CHANGELOG.md                           |  2 +-
 packages/core-js/modules/es.promise.js | 27 ++++++++++++--------------
 2 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fee673e64255..31d27b5d7065 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 ## Changelog
 ##### Unreleased
-- Made `instanceof Promise` work with polyfilled `Promise` for all native promise-based APIs
+- Made `instanceof Promise` and `.constructor === Promise` work with polyfilled `Promise` for all native promise-based APIs
 
 ##### 3.11.0 - 2021.04.22
 - Added [accessible `Object#hasOwnProperty` stage 2 proposal](https://github.com/tc39/proposal-accessible-object-hasownproperty)
diff --git a/packages/core-js/modules/es.promise.js b/packages/core-js/modules/es.promise.js
index eaafc83bf169..7fed1200a004 100644
--- a/packages/core-js/modules/es.promise.js
+++ b/packages/core-js/modules/es.promise.js
@@ -33,11 +33,11 @@ var PROMISE = 'Promise';
 var getInternalState = InternalStateModule.get;
 var setInternalState = InternalStateModule.set;
 var getInternalPromiseState = InternalStateModule.getterFor(PROMISE);
+var NativePromisePrototype = NativePromise && NativePromise.prototype;
 var PromiseConstructor = NativePromise;
 var TypeError = global.TypeError;
 var document = global.document;
 var process = global.process;
-var $fetch = getBuiltIn('fetch');
 var newPromiseCapability = newPromiseCapabilityModule.f;
 var newGenericPromiseCapability = newPromiseCapability;
 var DISPATCH_EVENT = !!(document && document.createEvent && global.dispatchEvent);
@@ -284,11 +284,11 @@ if (FORCED) {
       : newGenericPromiseCapability(C);
   };
 
-  if (!IS_PURE && typeof NativePromise == 'function') {
-    nativeThen = NativePromise.prototype.then;
+  if (!IS_PURE && typeof NativePromise == 'function' && NativePromisePrototype !== Object.prototype) {
+    nativeThen = NativePromisePrototype.then;
 
-    // wrap native Promise#then for native async functions
-    redefine(NativePromise.prototype, 'then', function then(onFulfilled, onRejected) {
+    // make `Promise#then` return a polyfilled `Promise` for native promise-based APIs
+    redefine(NativePromisePrototype, 'then', function then(onFulfilled, onRejected) {
       var that = this;
       return new PromiseConstructor(function (resolve, reject) {
         nativeThen.call(that, resolve, reject);
@@ -296,18 +296,15 @@ if (FORCED) {
     // https://github.com/zloirock/core-js/issues/640
     }, { unsafe: true });
 
-    // make `instanceof Promise` work for all native promise-based APIs
+    // make `.constructor === Promise` work for native promise-based APIs
+    try {
+      delete NativePromisePrototype.constructor;
+    } catch (error) { /* empty */ }
+
+    // make `instanceof Promise` work for native promise-based APIs
     if (setPrototypeOf) {
-      setPrototypeOf(NativePromise.prototype, PromiseConstructor.prototype);
+      setPrototypeOf(NativePromisePrototype, PromiseConstructor.prototype);
     }
-
-    // wrap fetch result, TODO: drop it in `core-js@4` in favor of workaround above
-    if (typeof $fetch == 'function') $({ global: true, enumerable: true, forced: true }, {
-      // eslint-disable-next-line no-unused-vars -- required for `.length`
-      fetch: function fetch(input /* , init */) {
-        return promiseResolve(PromiseConstructor, $fetch.apply(global, arguments));
-      }
-    });
   }
 }