From 95eef872be4d812c129fcc976caddc0a3446b5e6 Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Wed, 15 Nov 2023 20:30:08 +0700
Subject: [PATCH] Protect against improper use in classes

Fixes #8
---
 index.js |  4 ++++
 test.js  | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/index.js b/index.js
index bbc1e73..bdd851f 100644
--- a/index.js
+++ b/index.js
@@ -24,6 +24,10 @@ function debounce(function_, wait = 100, immediate) {
 	}
 
 	const debounced = function (...arguments_) {
+		if (storedContext && this !== storedContext) {
+			throw new Error('Debounced method called with different contexts.');
+		}
+
 		storedContext = this; // eslint-disable-line unicorn/no-this-assignment
 		storedArguments = arguments_;
 		timestamp = Date.now();
diff --git a/test.js b/test.js
index c31d43c..d2114e0 100644
--- a/test.js
+++ b/test.js
@@ -173,3 +173,28 @@ describe('forcing execution', () => {
 		expect(callback.args[2]).toEqual([1]);
 	});
 });
+
+describe('context check in debounced function', () => {
+	it('should throw an error if debounced method is called with different contexts', () => {
+		function MyClass() {}
+
+		MyClass.prototype.debounced = debounce(() => {});
+
+		const instance1 = new MyClass();
+		const instance2 = new MyClass();
+
+		// Call the debounced function on the first instance
+		instance1.debounced();
+
+		let errorThrown = false;
+		try {
+			// Attempt to call the same debounced function on a different instance
+			instance2.debounced();
+		} catch (error) {
+			errorThrown = true;
+			expect(error.message).toEqual('Debounced method called with different contexts.');
+		}
+
+		expect(errorThrown).toBeTruthy();
+	});
+});