util: runtime deprecate util.isObject

PR-URL: #50488
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Yagiz Nizipli <yagiz.nizipli@sentry.io>
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

doc/api/deprecations.md

@@ -1175,6 +1175,9 @@ The [`util.isNumber()`][] API is deprecated.
 
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/50488
+    description: Runtime deprecation.
   - version:
     - v6.12.0
     - v4.8.6
@@ -1187,7 +1190,7 @@ changes:
     description: Documentation-only deprecation.
 -->
 
-Type: Documentation-only
+Type: Runtime
 
 The [`util.isObject()`][] API is deprecated.
 

lib/util.js

@@ -427,7 +427,8 @@ module.exports = {
                       'The `util.isRegExp` API is deprecated. Please use `arg instanceof RegExp` instead.',
                       'DEP0055'),
   isObject: deprecate(isObject,
-                      'The `util.isObject` API is deprecated. Please use `typeof arg === "object"` instead.',
+                      'The `util.isObject` API is deprecated. ' +
+                      'Please use `arg !== null && typeof arg === "object"` instead.',
                       'DEP0053'),
   isDate: deprecate(types.isDate,
                     'The `util.isDate API is deprecated.  Please use `arg instanceof Error` instead.',