feat: use a global symbol for util.promisify.custom

Define `util.promisify.custom` as `Symbol.for("nodejs.util.inspect.custom")`, rather than as `Symbol("util.inspect.custom")`. This allows custom `promisify` wrappers to easily/safely be defined in non‑Node.js environments. Refs: nodejs/node#31647 Refs: nodejs/node#31672
EB-Forks · Feb 8, 2020 · f89af7d · f89af7d
1 parent 3c89541
commit f89af7d
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/util.js b/util.js
@@ -607,7 +607,10 @@ function hasOwnProperty(obj, prop) {
   return Object.prototype.hasOwnProperty.call(obj, prop);
 }
 
-var kCustomPromisifiedSymbol = typeof Symbol !== 'undefined' ? Symbol('util.promisify.custom') : undefined;
+var kCustomPromisifiedSymbol =
+  typeof Symbol === 'function' && typeof Symbol['for'] === 'function'
+    ? Symbol['for']('nodejs.util.promisify.custom')
+    : undefined;
 
 exports.promisify = function promisify(original) {
   if (typeof original !== 'function')