implemented repeatStr and added Jest tests

Author: Zadri415

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

@@ -1,7 +1,16 @@
-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).
-  // The goal is to re-implement that function, not to use it.
-  return "hellohellohello";
+function repeatStr(str, count) {
+  if (typeof str !== "string") {
+    throw new TypeError("First argument must be a string");
+  }
+  if (!Number.isInteger(count) || count < 0) {
+    throw new TypeError("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

@@ -20,13 +20,99 @@ 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 return the original string when count is 1", () => {
+  const str = "world";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).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", () => {
+  const str = "test";
+  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`,
 // 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 for negative count", () => {
+  const str = "error";
+  const count = -2;
+  expect(() => repeatStr(str, count)).toThrow(
+    "Count must be a non-negative integer"
+  );
+});
+
+test("should throw an error for non-integer count", () => {
+  const str = "error";
+  const count = 2.5;
+  expect(() => repeatStr(str, count)).toThrow(
+    "Count must be a non-negative integer"
+  );
+});
+
+test("should throw an error for non-string input", () => {
+  const str = 123;
+  const count = 3;
+  expect(() => repeatStr(str, count)).toThrow(
+    "First argument must be a string"
+  );
+});
+
+test("should throw an error for null or undefined input", () => {
+  const count = 3;
+  expect(() => repeatStr(null, count)).toThrow(
+    "First argument must be a string"
+  );
+  expect(() => repeatStr(undefined, count)).toThrow(
+    "First argument must be a string"
+  );
+});
+
+test("handle empty string input", () => {
+  const str = "";
+  const count = 5;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
+test("handle large count input", () => {
+  const str = "a";
+  const count = 1000;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("a".repeat(count));
+});
+
+test("handle special characters in string", () => {
+  const str = "!@#";
+  const count = 4;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("!@#!@#!@#!@#");
+});
+
+test("handle whitespace in string", () => {
+  const str = " ";
+  const count = 3;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("   ");
+});
+
+test("repeats unicode characters correctly", () => {
+  const str = "😊";
+  const count = 5;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("😊😊😊😊😊");
+});
+
+test("handles empty string", () => {
+  const str = "";
+  const count = 5;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});