Added code and test to throw an error.. it is at this time I was reading the task again and see I must not use .repeat.... here we go again then ^_^

Author: HM-127BTY

practice-tdd/repeat-str.js

@@ -1,5 +1,8 @@
 export function repeatStr(str, count) {
   // Your implementation of this function must *not* call String.prototype.repeat (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat).
   // The goal is to re-implement that function, not to use it.
+  if (count < 0) {
+    throw new Error("negative counts are not valid");
+  }
   return str.repeat(count);
 }

practice-tdd/repeat-str.test.js

@@ -8,8 +8,7 @@ import { repeatStr } from "./repeat-str.js";
 // Given a target string `str` and a positive integer `count` greater than 1,
 // When the repeatStr function is called with these inputs,
 // Then it should return a string that contains the original `str` repeated `count` times.
-
-test("should repeat the string count times", () => {
+test("should repeat the string count 3 times", () => {
   const str = "hello";
   const count = 3;
   const repeatedStr = repeatStr(str, count);
@@ -20,7 +19,7 @@ test("should repeat the string count times", () => {
 // Given a target string `str` and a `count` equal to 1,
 // When the repeatStr function is called with these inputs,
 // Then it should return the original `str` without repetition.
-test("should repeat the string count times", () => {
+test("should repeat the string count 1 times", () => {
   const str = "hello";
   const count = 1;
   const repeatedStr = repeatStr(str, count);
@@ -31,7 +30,7 @@ test("should repeat the string count times", () => {
 // Given a target string `str` and a `count` equal to 0,
 // When the repeatStr function is called with these inputs,
 // Then it should return an empty string.
-test("should repeat the string count times", () => {
+test("should repeat the string count 0 times", () => {
   const str = "hello";
   const count = 0;
   const repeatedStr = repeatStr(str, count);
@@ -42,3 +41,9 @@ test("should repeat the string count times", () => {
 // Given a target string `str` and a negative integer `count`,
 // When the repeatStr function is called with these inputs,
 // Then it should throw an error, as negative counts are not valid.
+test("should throw an error 'negative counts are not valid'", () => {
+  const str = "hello";
+  const count = -3;
+  expect(() => repeatedStr(str, count)).toThrow;
+  new Error("negative counts are not valid");
+});