receive message from IBM MQ in js app

[pavloNP]

Hi! I need to receive messages from IBM MQ in a js app.
The goal is:
1. Receive a message
2. Make several operations with date
3. When all operations are finished, make the same with the second message.

I face a problem. The await isn't worked. And I receive all messages and can't work in the "synchronic style" one after one.

const mq = require("ibmmq");
const { loadBaselineFile, dbStatus } = require("./dbLoader");
const dbl = require("./dbLoader");

const logger = require("../config/logerConfig");
const fs = require("fs");
const MQC = mq.MQC;

const StringDecoder = require("string_decoder").StringDecoder;
const decoder = new StringDecoder("utf8");

const qMgr = "QM1";
const qName = "TEST.QUEUE";
const msgId = null;

let connectionHandle;
let queueHandle;
let count = 0;

module.exports = { startListeningMQ };
function startListeningMQ() {
const cno = new mq.MQCNO();

const csp = new mq.MQCSP();
csp.UserId = "mqm";
csp.Password = "mqm";
cno.SecurityParms = csp;

cnptions |= MQC.MQCNO_CLIENT_BINDING;
const cd = new mq.MQCD();
cd.ConnectionName = "localhost(1414)";
cd.ChannelName = "SVRCONN";
cno.ClientConn = cd;

mq.Conn(qMgr, function(err, hConn) {
if (err) {
console.log(formatErr(err));
} else {
console.log("MQCONN to %s successful ", qMgr);
connectionHandle = hConn;

const od = new mq.MQOD();
od.ObjectName = qName;
od.ObjectType = MQC.MQOT_Q;
const openOptions = MQC.MQOO_BROWSE;
mq.Open(hConn, od, openOptions, function(err, hObj) {
queueHandle = hObj;
if (err) {
console.log(formatErr(err));
} else {
console.log("MQOPEN of %s successful", qName);
getMessages();
}
});
}
});
}

function getMessages() {
const md = new mq.MQMD();
const gmo = new mq.MQGMO();

gmptions =
MQC.MQGMO_NO_SYNCPOINT |
MQC.MQGMO_WAIT |
MQC.MQGMO_CONVERT |
MQC.MQGMO_FAIL_IF_QUIESCING |
MQC.MQGMO_MQWI_UNLIMITED;
gmptions |= MQC.MQGMO_BROWSE_NEXT;

gmo.MatchOptions = MQC.MQMO_NONE;

if (msgId != null) {
console.log("Setting Match Option for MsgId");
gmo.MatchOptions = MQC.MQMO_MATCH_MSG_ID;
md.MsgId = hexToBytes(msgId);
}

mq.setTuningParameters({ getLoopPollTimeMs: 500 });
mq.Get(queueHandle, md, gmo, getCB);
}

function hexToBytes(hex) {
for (const bytes = [], c = 0; c < hex.length; c += 2)
bytes.push(parseInt(hex.substr(c, 2), 16));
return bytes;
}

async function getCB(err, hObj, gmo, md, buf, hConn) {
if (err) {
if (err.mqrc == MQC.MQRC_NO_MSG_AVAILABLE) {
console.log("No more messages available.");
} else {
console.log(formatErr(err));
exitCode = 1;
}
ok = false;
mq.GetSync(hObj);
} else {
if (md.Format == "MQSTR") {
console.log("message <%s>", decoder.write(buf));
count++;
try {
fs.writeFileSync(
"data_loader/dataForLoad/tryAgain" + count + ".json",
decoder.write(buf),
"utf8"
);
} catch (e) {
console.log("Cannot write file ", e);
}

const filePath =
`file:///home` +
`myfile.json`;
logger.serverLogger().info(`Start to upload BASELINE file ${filePath}`);


await MYFUNCTION(filePath);
gmptions &= ~MQC.MQGMO_BROWSE_FIRST;
gmptions |= MQC.MQGMO_BROWSE_NEXT;

} else {
console.log("binary message: " + buf);
}
}
}

function formatErr(err) {
if (err) {
ok = false;
return "MQ call failed at " + err.message;
} else {
return "MQ call successful";
}
}

function sleep {
setTimeout(function() {}, ms);
}