From 17467d15f8e0494579c32acf576240a346e82c2b Mon Sep 17 00:00:00 2001
From: cjihrig <cjihrig@gmail.com>
Date: Tue, 26 Jan 2021 23:15:56 -0500
Subject: [PATCH] util: add internal createDeferredPromise()
MIME-Version: 1.0
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The pattern of resolving/rejecting a Promise from outside of its
executor happens numerous times throughout the codebase (more than
what is updated here in fact). This commit abstracts that logic
into an internal utility function.

PR-URL: https://github.com/nodejs/node/pull/37095
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/child_process.js |  9 ++-------
 lib/internal/blob.js | 13 ++-----------
 lib/internal/util.js | 12 ++++++++++++
 3 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/lib/child_process.js b/lib/child_process.js
index 02a12010c5ca56..74699a16834c30 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -37,7 +37,6 @@ const {
   ObjectAssign,
   ObjectDefineProperty,
   ObjectPrototypeHasOwnProperty,
-  Promise,
   RegExpPrototypeTest,
   SafeSet,
   StringPrototypeSlice,
@@ -47,6 +46,7 @@ const {
 const {
   promisify,
   convertToValidSignal,
+  createDeferredPromise,
   getSystemErrorName
 } = require('internal/util');
 const { isArrayBufferView } = require('internal/util/types');
@@ -185,12 +185,7 @@ function exec(command, options, callback) {
 
 const customPromiseExecFunction = (orig) => {
   return (...args) => {
-    let resolve;
-    let reject;
-    const promise = new Promise((res, rej) => {
-      resolve = res;
-      reject = rej;
-    });
+    const { promise, resolve, reject } = createDeferredPromise();
 
     promise.child = orig(...args, (err, stdout, stderr) => {
       if (err !== null) {
diff --git a/lib/internal/blob.js b/lib/internal/blob.js
index e49b3710e0768a..82b375da783fe1 100644
--- a/lib/internal/blob.js
+++ b/lib/internal/blob.js
@@ -3,7 +3,6 @@
 const {
   ArrayFrom,
   ObjectSetPrototypeOf,
-  Promise,
   PromiseResolve,
   RegExpPrototypeTest,
   StringPrototypeToLowerCase,
@@ -29,6 +28,7 @@ const {
 } = require('internal/util/types');
 
 const {
+  createDeferredPromise,
   customInspectSymbol: kInspect,
   emitExperimentalWarning,
 } = require('internal/util');
@@ -56,15 +56,6 @@ const kLength = Symbol('kLength');
 
 let Buffer;
 
-function deferred() {
-  let res, rej;
-  const promise = new Promise((resolve, reject) => {
-    res = resolve;
-    rej = reject;
-  });
-  return { promise, resolve: res, reject: rej };
-}
-
 function lazyBuffer() {
   if (Buffer === undefined)
     Buffer = require('buffer').Buffer;
@@ -210,7 +201,7 @@ class Blob extends JSTransferable {
       promise,
       resolve,
       reject
-    } = deferred();
+    } = createDeferredPromise();
     job.ondone = (err, ab) => {
       if (err !== undefined)
         return reject(new AbortError());
diff --git a/lib/internal/util.js b/lib/internal/util.js
index 5d5a2b14a708b4..46eabc6f08c092 100644
--- a/lib/internal/util.js
+++ b/lib/internal/util.js
@@ -420,11 +420,23 @@ function sleep(msec) {
   _sleep(msec);
 }
 
+function createDeferredPromise() {
+  let resolve;
+  let reject;
+  const promise = new Promise((res, rej) => {
+    resolve = res;
+    reject = rej;
+  });
+
+  return { promise, resolve, reject };
+}
+
 module.exports = {
   assertCrypto,
   cachedResult,
   convertToValidSignal,
   createClassWrapper,
+  createDeferredPromise,
   decorateErrorStack,
   deprecate,
   emitExperimentalWarning,