Synchronous NodeJS batch job - node.js

Question

I'm trying to write a batch script that will
Read XMLs from a directory
Parse each XML and find a value to use for DB(database) Lookup
Use the parsed value to DB lookup additional metadata
Populate XML with the metadata retrieved from DB lookup (step 4)
Write updated XML to complete directory
Close DB connection
The issue I'm running into is that I cannot control the code execution order so that I can close the DB connection at the end of the script. If I attempt to close the connection, I get a 'connection undefined' error. Below is my code for reference. Is there a good way to accomplish something like this in NodeJs, or should I look at doing this in Java or some other language?
enter code here
'use strict';
let fs = require('fs');
let xml2js = require('xml2js');
const oracledb = require('oracledb');
const dbConfig = require('./dbconfig.js');
function pad(number, length)
{
var str = '' + number;
while (str.length < length)
{
str = '0' + str;
}
return str;
}
async function run() {
try {
// Get a non-pooled connection
let connection;
if (!connection)
{
connection = await oracledb.getConnection(dbConfig);
console.log('Connection was successful!');
}
let directory = "EDI_XMLS";
let dirBuf = Buffer.from(directory);
//var f = 0;
let files = fs.readdirSync(directory);
console.log(files);
for (let f = 0; f < files.length; f++)
{
let parser = new xml2js.Parser();
var xml_json_data = "";
// read the file
await fs.readFile(directory + "/" + files[f], async function(err, data) {
// parse the file
await parser.parseString(data, async function(err, result) {
let results;
var line_count = result.page.GLLines[0].GLLine.length;
console.dir('Invoice: ' + result.page.InvoiceNumber[0]);
console.dir('Line Total: ' + line_count);
console.log('File: ' + f);
try
{ // Lookup Data
results = await connection.execute('SELECT BUSINESS_UNIT, OPERATING_UNIT, DEPTID,PRODUCT,a.effdt FROM SYSADM.PS_A_NSS_SHPTO_ACC#FDEV a where(a.a_ship_to_customer = :shipTo) order by a.effdt
desc',[pad(result.page.VoucherDescription[0], 10)], {
maxRows: 2
});
console.log(results.metaData);
console.log(results.rows);
}
catch (err)
{
console.error(err);
}
for (let i = 0; i < line_count; i++) // Populate data
{
result.page.GLLines[0].GLLine[i].GLBU[0] = results.rows[0][0];
result.page.GLLines[0].GLLine[i].OpUnit[0] = results.rows[0[1];
result.page.GLLines[0].GLLine[i].Department[0] = results.rows[0][2];
result.page.GLLines[0].GLLine[i].Product[0] = results.rows[0][3];
}
// Write to File
var builder = new xml2js.Builder();
var xml = builder.buildObject(result);
await fs.writeFile("complete/" + files[f], xml, function(err, data) {
if (err) console.log(err);
console.log("successfully written our update xml to file");
console.dir('BUs: ' + JSON.stringify(result.page));
}); //end write
}); //end parser
}); //end readfile
console.log('End');
} // async for
}
catch (err)
{
console.error(err);
}
finally
{
await connection.close();
console.log('Finally Done');
}
}
run();
console.log('completely Done');