AES-256 string encryption / decryption

/* --- Code ready to copy -> paste -> run --- */
// Libraries
const crypto = require('crypto');
const ENCODING = "hex"; // hex or base64

// Implementations
function encryptAES256(clearMsg, key) {
    let iv = crypto.randomBytes(16); // Generating 16 byte random IV
    let cipher = crypto.createCipheriv(
        "aes256",
        crypto.createHash("sha256").update(key, "utf8").digest(), // 32 bytes always for the key
        iv);
    return (Buffer.concat([
        iv, // Adding the IV at the beginning of the encrypted message (https://nodejs.org/dist/latest-v16.x/docs/api/crypto.html#crypto_crypto_createcipheriv_algorithm_key_iv_options)
        cipher.update(clearMsg),
        cipher.final()
    ])).toString(ENCODING);
}

function decryptAES256(encMsg, key) {
    let decipher = crypto.createDecipheriv(
        "aes256",
        crypto.createHash("sha256").update(key, "utf8").digest(), // 32 bytes always for the key
        Buffer.from(encMsg, ENCODING).slice(0, 16) // Extracting the IV from the encrypted string (16 bytes)
    );
    return (Buffer.concat([
        decipher.update(Buffer.from(encMsg, ENCODING).slice(16)), // Extracting the encrypted message from the encrypted string
        decipher.final()
    ])).toString('utf8');
}

// Exporting the functions to use it as a module
// module.exports.encryptAES256 = encryptAES256;
// module.exports.decryptAES256 = decryptAES256;

// Demo / Test
let e = encryptAES256("Hello World!", "test");
console.log("> Encrpyted: " + e);

let d = decryptAES256(e, "test");
console.log("> Decrpyted: " + d);