Implement repeatStr function

Author: MahirShah300

practice-tdd/repeat-str.js

@@ -1,5 +1,14 @@
-export function repeatStr() {
+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.
-  return "hellohellohello";
+  if (count < 0) {
+    throw new Error("Error - invalid count number");
+  }
+
+  let repeatedStr = "";
+  for (let i = count; i > 0; i--) {
+    repeatedStr += str;
+  }
+
+  return repeatedStr;
 }