Implement repeatStr with tests

Author: eyob-tech

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

@@ -1,7 +1,15 @@
-function repeatStr() {
-  // 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).
+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("count must not be negative");
+  }
+
+  let result = "";
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+  return result;
 }
 
-module.exports = repeatStr;
+module.exports = repeatStr;

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

@@ -1,13 +1,13 @@
 // Implement a function repeatStr
 const repeatStr = require("./repeat-str");
-// Given a target string `str` and a positive integer `count`,
+// Given a target string str and a positive integer count,
 // When the repeatStr function is called with these inputs,
 // Then it should:
 
 // Case: handle multiple repetitions:
-// Given a target string `str` and a positive integer `count` greater than 1,
+// 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.
+// Then it should return a string that contains the original str repeated count times.
 
 test("should repeat the string count times", () => {
   const str = "hello";
@@ -17,16 +17,36 @@ test("should repeat the string count times", () => {
 });
 
 // Case: handle count of 1:
-// Given a target string `str` and a `count` equal to 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.
+// Then it should return the original str without repetition.
+
+test("should return the original string when count is 1", () => {
+  const str = "hello";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("hello");
+});
 
 // Case: Handle count of 0:
-// Given a target string `str` and a `count` equal to 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", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
 // Case: Handle negative count:
-// Given a target string `str` and a negative integer `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", () => {
+  const str = "hello";
+  const count = -1;
+  expect(() => repeatStr(str, count)).toThrow();
+});