Convert hex string to ArrayBuffer

hexStringToArrayBuffer.js

/**
 * Convert a hex string to an ArrayBuffer.
 * 
 * @param {string} hexString - hex representation of bytes
 * @return {ArrayBuffer} - The bytes in an ArrayBuffer.
 */
function hexStringToArrayBuffer(hexString) {
    // remove the leading 0x
    hexString = hexString.replace(/^0x/, '');
    
    // ensure even number of characters
    if (hexString.length % 2 != 0) {
        console.log('WARNING: expecting an even number of characters in the hexString');
    }
    
    // check for some non-hex characters
    var bad = hexString.match(/[G-Z\s]/i);
    if (bad) {
        console.log('WARNING: found non-hex characters', bad);    
    }
    
    // split the string into pairs of octets
    var pairs = hexString.match(/[\dA-F]{2}/gi);
    
    // convert the octets to integers
    var integers = pairs.map(function(s) {
        return parseInt(s, 16);
    });
    
    var array = new Uint8Array(integers);
    console.log(array);
    
    return array.buffer;
}