Completed repeatStr implementation - passes all 5 Jest test cases

Author: Eugenie-A

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

@@ -1,5 +1,26 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  // Reject negative counts - not valid for repetition
+  if (count < 0) {
+    throw new Error("Count cannot be negative");
+  }
+
+  // If count is 0, return empty string immediately
+  if (count === 0) {
+    return "";
+  }
+
+  // For count = 1, just return the original string
+  if (count === 1) {
+    return str;
+  }
+
+  // For count > 1: build the repeated string using a loop
+  let result = "";
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+
+  return result;
 }
 
 module.exports = repeatStr;