Parsing advertisement js

advertisement.js

function parseAdvertisingData(buffer) {
    var length, type, data, i = 0, advertisementData = {};
    var bytes = new Uint8Array(buffer);

    while (length !== 0) {

        length = bytes[i] & 0xFF;
        i++;

        // decode type constants from https://www.bluetooth.org/en-us/specification/assigned-numbers/generic-access-profile
        type = bytes[i] & 0xFF;
        i++;

        data = bytes.slice(i, i + length - 1).buffer; // length includes type byte, but not length byte
        i += length - 2;  // move to end of data
        i++;

        advertisementData[asHexString(type)] = data;
    }

    return advertisementData;
}