Implement repeatStr function with input validation and enhance test coverage

Author: mervereis

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

@@ -1,5 +1,14 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  if (typeof count !== "number" || count < 0) {
+    throw new Error("Count must be a non-negative integer");
+  }
+
+  let result = "";
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+
+  return result;
 }
 
 module.exports = repeatStr;

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

@@ -10,23 +10,40 @@ const repeatStr = require("./repeat-str");
 // Then it should return a string that contains the original `str` repeated `count` times.
 
 test("should repeat the string count times", () => {
-  const str = "hello";
-  const count = 3;
-  const repeatedStr = repeatStr(str, count);
-  expect(repeatedStr).toEqual("hellohellohello");
+  expect(repeatStr("hello", 3)).toEqual("hellohellohello");
 });
 
 // Case: handle count of 1:
 // 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 return the original string when count is 1", () => {
+  expect(repeatStr("world", 1)).toEqual("world");
+});
+
 // Case: Handle count of 0:
 // 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 return an empty string when count is 0", () => {
+  expect(repeatStr("test", 0)).toEqual("");
+});
+
 // Case: Handle negative count:
 // 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 when count is negative", () => {
+  expect(() => {
+    repeatStr("error", -2);
+  }).toThrow("Count must be a non-negative integer");
+});
+
+test("should throw an error when count is not a number", () => {
+  expect(() => {
+    repeatStr("error", "-2");
+  }).toThrow("Count must be a non-negative integer");
+});