FIX: support isPlainObj with constructor keys (immutable-js#1627)

leebyron · web-flow · commit 6203e2af0fc7 · 2018-10-26T18:14:25.000-07:00
Specifically look for a function instead of any value Closes immutable-js#1623
diff --git a/src/utils/isPlainObj.js b/src/utils/isPlainObj.js
@@ -8,7 +8,7 @@
 export default function isPlainObj(value) {
   return (
     value &&
-    ((value.constructor && value.constructor.name === 'Object') ||
-      value.constructor === undefined)
+    (typeof value.constructor !== 'function' ||
+      value.constructor.name === 'Object')
   );
 }
