utils.js

'use strict';

let sleep = ms => new Promise(r => setTimeout(r, ms));
let waitFor = async function waitFor(f) {
    while (!f()) await sleep(100 + Math.random() * 25);
    return f();
};

let waitForTimeout = async function waitFor(f, timeoutSec) {
    var totalTimeMs = 0;
    while (!f() && totalTimeMs < timeoutSec * 1000) {
        var delayMs = 100 + Math.random() * 25;
        totalTimeMs += delayMs;
        await sleep(delayMs);
    }
    return f();
};

/**
 * Helper function to convert a value into an enum value
 * 
 * @param {type} enumtype
 * @param {number} enumvalue
 */
 function Parse(enumtype, enumvalue) {
    for (var enumName in enumtype) {
        if (enumtype[enumName] == enumvalue) {
            /*jshint -W061 */
            return eval([enumtype + "." + enumName]);
        }
    }
    return null;
}

/**
 * Helper function to dump arraybuffer as hex string
 * @param {ArrayBuffer} buffer
 */
 function buf2hex(buffer) { // buffer is an ArrayBuffer
    return [...new Uint8Array(buffer)]
        .map(x => x.toString(16).padStart(2, '0'))
        .join(' ');
}

function hex2buf (input) {
    if (typeof input !== 'string') {
        throw new TypeError('Expected input to be a string')
    }
    var hexstr = input.replace(/\s+/g, '');
    if ((hexstr.length % 2) !== 0) {
        throw new RangeError('Expected string to be an even number of characters')
    }

    const view = new Uint8Array(hexstr.length / 2)

    for (let i = 0; i < hexstr.length; i += 2) {
        view[i / 2] = parseInt(hexstr.substring(i, i + 2), 16)
    }

    return view.buffer
}

module.exports = { sleep, waitFor, waitForTimeout, Parse, buf2hex, hex2buf };