fix: do not deep convert buffers

index.js

@@ -18,9 +18,7 @@ const cache = new QuickLru({maxSize: 100_000});
 const isObject = value =>
 	typeof value === 'object'
 		&& value !== null
-		&& !(value instanceof RegExp)
-		&& !(value instanceof Error)
-		&& !(value instanceof Date);
+		&& (Array.isArray(value) || Object.getPrototypeOf(value) === Object.prototype);
 
 const transform = (input, options = {}) => {
 	if (!isObject(input)) {

test.js

@@ -1,6 +1,7 @@
 import process from 'node:process';
 import {promisify} from 'node:util';
 import {execFile} from 'node:child_process';
+import {Buffer} from 'node:buffer';
 import test from 'ava';
 import camelcaseKeys from './index.js';
 
@@ -136,6 +137,11 @@ test('use locale independent camel-case transformation', async t => {
 	);
 });
 
+test('do not deep convert buffer', t => {
+	const input = {foo: Buffer.from('foo')};
+	t.true(camelcaseKeys(input, {deep: true}).foo instanceof Buffer);
+});
+
 /**
 Executes the library with the given arguments and resolves with the parsed result.