From e7e2213e9100a4212caf28c4af49efdaa9c83354 Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Sun, 15 Oct 2023 16:01:29 +0700
Subject: [PATCH] `directInstanceOf`: Fix handling of `undefined` and `null`

Fixes #199
---
 source/index.ts | 4 ++++
 test/test.ts    | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/source/index.ts b/source/index.ts
index 782a067..848af80 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -413,6 +413,10 @@ export function isDate(value: unknown): value is Date {
 }
 
 export function isDirectInstanceOf<T>(instance: unknown, class_: Class<T>): instance is T {
+	if (instance === undefined || instance === null) {
+		return false;
+	}
+
 	return Object.getPrototypeOf(instance) === class_.prototype;
 }
 
diff --git a/test/test.ts b/test/test.ts
index 8608a25..bbf7b57 100644
--- a/test/test.ts
+++ b/test/test.ts
@@ -986,6 +986,9 @@ test('is.directInstanceOf', t => {
 	t.throws(() => {
 		assert.directInstanceOf(errorSubclass, Error);
 	});
+
+	t.false(is.directInstanceOf(undefined, Error));
+	t.false(is.directInstanceOf(null, Error));
 });
 
 test('is.urlInstance', t => {