feat(utils): add string reversal utility with TDD

.gitignore

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+node_modules/
+dist/
+.env
+.env.local
+.env.*.local
+*.log
+.DS_Store
+coverage/

README.md

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-# nodejs-practice-repository
+# nodejs-practice-repository
+
+A Node.js practice repo for learning JavaScript utilities and TDD.
+
+## Getting Started
+
+**Prerequisites:** Node.js and npm installed.
+
+```bash
+# Clone the repo
+git clone https://github.com/jbb-codes/nodejs-practice-repository.git
+cd nodejs-practice-repository
+
+# Install dependencies
+npm install
+
+# Run tests
+npm test
+```

src/utils/reverseString.js

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+/**
+ * Author: Jarren Bess
+ * Date: 2 June 2026
+ * File: reverseString.js
+ * Description: Utility function to reverse a string.
+ */
+"use strict";
+
+function reverseString(str) {
+  if (typeof str !== "string") {
+    throw new Error("Input must be a string");
+  }
+
+  return str.split("").reverse().join("");
+}
+
+module.exports = { reverseString };

test/utils/reverseString.spec.js

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+/**
+ * Author: Jarren Bess
+ * Date: 2 June 2026
+ * File: reverseString.spec.js
+ * Description: Tests for the reverseString utility function.
+ */
+"use strict";
+
+const { reverseString } = require("../../src/utils/reverseString");
+
+describe("reverseString", () => {
+  it("should reverse a regular string", () => {
+    const result = reverseString("hello");
+    expect(result).toBe("olleh");
+  });
+
+  it("should return an empty string when given an empty string", () => {
+    const result = reverseString("");
+    expect(result).toBe("");
+  });
+
+  it("should throw an error when given a non-string input", () => {
+    expect(() => reverseString(123)).toThrow("Input must be a string");
+  });
+});