fix: avoid duplicate parameter names (#12)

* add test case to capture duplicate parameter name

* skip reserved names by using '0' as a suffix instead of '_'

src/index.ts

@@ -227,7 +227,7 @@ function getName(num: number) {
 		num = ~~(num / chars.length) - 1;
 	} while (num >= 0);
 
-	return reserved.test(name) ? `${name}_` : name;
+	return reserved.test(name) ? `${name}0` : name;
 }
 
 function isPrimitive(thing: any) {

test/test.ts

@@ -144,5 +144,12 @@ describe('devalue', () => {
 		//
 		test('objects with symbolic keys', { [Symbol()]: null, 'key': 'val' }, '{key:"val"}');
 
+		it('do not have duplicates in generated argument names', () => {
+			const foo = new Array(20000).fill(0).map((_, i) => i);
+			const bar = foo.map((_, i) => ({ [i]: foo[i] }));
+			const serialized = devalue([foo, ...bar]);
+
+			assert.doesNotThrow(() => eval(serialized), /Duplicate parameter name/);
+		});
 	});
 });