I added the error message to improve the code and the test

Author: Oussama-Mouggal

Sprint-3/2-practice-tdd/repeat-str.test.js

@@ -35,7 +35,7 @@ test("should return an empty string when count is 0", () => {
 test("should throw an error when count is negative", () => {
   const str = "hello";
   const count = -1;
-  expect(() => repeatStr(str, count)).toThrow();
+  expect(() => repeatStr(str, count)).toThrow("Count must be non-negative");
 });
 // Case: handle count of 1:
 // Given a target string `str` and a `count` equal to 1,