Fix the class context validation (#43)

Author: oleksandr-danylchenko

index.js

@@ -40,8 +40,12 @@ function debounce(function_, wait = 100, options = {}) {
 	}
 
 	const debounced = function (...arguments_) {
-		if (storedContext && this !== storedContext) {
-			throw new Error('Debounced method called with different contexts.');
+		if (
+			storedContext
+			&& this !== storedContext
+			&& Object.getPrototypeOf(this) === Object.getPrototypeOf(storedContext)
+		) {
+			throw new Error('Debounced method called with different contexts of the same prototype.');
 		}
 
 		storedContext = this; // eslint-disable-line unicorn/no-this-assignment

test.js

@@ -147,7 +147,7 @@ test('forcing execution', async t => {
 });
 
 test('context check in debounced function', async t => {
-	await t.test('should throw an error if debounced method is called with different contexts', async () => {
+	await t.test('should throw an error if debounced method is called with different contexts of the same class', async () => {
 		function MyClass() {}
 
 		MyClass.prototype.debounced = debounce(() => {});
@@ -157,15 +157,32 @@ test('context check in debounced function', async t => {
 
 		instance1.debounced();
 
-		let errorThrown = false;
-		try {
+		assert.throws(() => {
 			instance2.debounced();
-		} catch (error) {
-			errorThrown = true;
-			assert.strictEqual(error.message, 'Debounced method called with different contexts.', 'Error message should match');
-		}
+		}, {
+			message: 'Debounced method called with different contexts of the same prototype.',
+		}, 'An error should have been thrown');
+	});
+
+	await t.test('should not throw an error if debounced method is called with different contexts of different classes', async () => {
+		function MyClass1() {}
+		function MyClass2() {}
+
+		const debouncedFunction = debounce(() => {});
+
+		MyClass1.prototype.debounced = debouncedFunction;
+		MyClass2.prototype.debounced = debouncedFunction;
 
-		assert.ok(errorThrown, 'An error should have been thrown');
+		const instance1 = new MyClass1();
+		const instance2 = new MyClass2();
+
+		instance1.debounced();
+
+		assert.doesNotThrow(() => {
+			instance2.debounced();
+		}, {
+			message: 'Debounced method called with different contexts of the same prototype.',
+		}, 'An error should not have been thrown');
 	});
 });