Bitfinex API for Google Apps Script

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Bitfinex API for Google Apps Script

This sample script is converted this sample script (javascript) to Google Apps Script. The point for converting is signature as shown in the following sample script.

• At Bitfinex API, after "/api/" + apiPath + nonce + rawBody is encrypted using HMAC SHA-384, the data of byte array is converted to HEX.
  • In Google Apps Script, there is no the method for this.
  • The data which was encrypted by Utilities.computeHmacSignature() is the bytes array of the signed hexadecimal.
  • On the other hand, at this sample script for javascript, the data which was encrypted by crypto.createHmac('sha384', apiSecret).update(signature).digest('hex') is the string of the unsigned hexadecimal.

In order to achieve above, I made the method of bytesToHex().

function bytesToHex(data) {
    return data.map(function(e) {
        var v = (e < 0 ? e + 256 : e).toString(16);
        return v.length == 1 ? "0" + v : v;
    }).join("");
}

function main() {
    const apiKey = '<Your API key here>';
    const apiSecret = '<Your API secret here>';

    const apiPath = "v2/auth/r/alerts";
    const nonce = Date.now().toString();
    const body = { "type": "price" };
    const rawBody = JSON.stringify(body);
    var signature = "/api/" + apiPath + nonce + rawBody;
    signature = Utilities.computeHmacSignature(Utilities.MacAlgorithm.HMAC_SHA_384, signature, apiSecret);
    signature = bytesToHex(signature);
    const url = "https://api.bitfinex.com/" + apiPath;
    const options = {
        method: 'POST',
        contentType: "application/json",
        headers: {
            'bfx-nonce': nonce,
            'bfx-apikey': apiKey,
            'bfx-signature': signature
        },
        payload: rawBody
    };
    var res = UrlFetchApp.fetch(url, options);
    Logger.log(res.getContentText())
}

This script is giving me the error TypeError: Cannot call method "map" of undefined. (line 2, file "Code").