From 45cae31f4d7311d8ae1250558e710594acff7d01 Mon Sep 17 00:00:00 2001
From: ehmicky <ehmicky@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:05:40 +0200
Subject: [PATCH] Improve `plainObject()` (#169)

---
 source/index.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/index.ts b/source/index.ts
index 4a3df85..3e68b19 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -286,14 +286,14 @@ is.safeInteger = (value: unknown): value is number => Number.isSafeInteger(value
 
 is.plainObject = <Value = unknown>(value: unknown): value is Record<PropertyKey, Value> => {
 	// From: https://github.com/sindresorhus/is-plain-obj/blob/main/index.js
-	if (toString.call(value) !== '[object Object]') {
+	if (typeof value !== 'object' || value === null) {
 		return false;
 	}
 
 	// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
 	const prototype = Object.getPrototypeOf(value);
 
-	return prototype === null || prototype === Object.getPrototypeOf({});
+	return (prototype === null || prototype === Object.prototype || Object.getPrototypeOf(prototype) === null) && !(Symbol.toStringTag in value) && !(Symbol.iterator in value);
 };
 
 is.typedArray = (value: unknown): value is TypedArray => isTypedArrayName(getObjectType(value));