test: Fix tests

Author: franky47

packages/nuqs/src/parsers.test.ts

@@ -33,8 +33,8 @@ describe('parsers', () => {
     expect(parseAsIndex.parse('1')).toBe(0)
     expect(parseAsIndex.parse('3.14')).toBe(2)
     expect(parseAsIndex.parse('3,14')).toBe(2)
-    expect(parseAsIndex.parse('0')).toBeNull()
-    expect(parseAsIndex.parse('-1')).toBeNull()
+    expect(parseAsIndex.parse('0')).toBe(-1)
+    expect(parseAsIndex.parse('-1')).toBe(-2)
     expect(parseAsIndex.serialize(0)).toBe('1')
     expect(parseAsIndex.serialize(3.14)).toBe('4')
   })