Appending array values to csv - node.js

Question

I would like to take some output and append the output to a csv
This is the code I have so far:
async function writeData() {
const csv = require('csv-parser')
const results = [];
fs.createReadStream('C:\\Users\\User\\Documents\\testingclean.csv')
.pipe(csv())
.on('data',(data)=> results.push(data))
.on('end', async () => {
const cookieJar = await getCookieJar();
const promises = [];
results.forEach((data) => {
promises.push(boxrec.getPersonById(cookieJar,data.id));
})
try {
const fighters = await Promise.all(promises);
fighters.forEach((fighter)=>{
boxer = JSON.parse(JSON.stringify(fighter.output));
fs.appendFile('C:\\Users\\User\\Documents\\newtest.csv',boxer, (err) => {
if (err) console.error('Could not append data to csv');
console.log('Data successfully appended');
})
});
} catch (e) {
console.log(e);
}
})
};
try {
writeData();
} catch (error) {
console.log("Error in writeData: " + error);
}
However running this code does not produce the desired csv output.
I am specifically writing to csv because I have read that I cannot append to a json (would ideally want to write data to a json)

Answer 1

If you don't have anything writen to the CSV file, you should close it explicitly at the end of your program :
var readsteam = fs.createReadStream();
...
readStream.destroy();
Not sure but this should be the full code :
async function writeData() {
const csv = require('csv-parser')
const results = [];
var readsteam = fs.createReadStream('C:\\Users\\User\\Documents\\testingclean.csv');
readsteam
.pipe(csv())
.on('data',(data)=> results.push(data))
.on('end', async () => {
const cookieJar = await getCookieJar();
const promises = [];
results.forEach((data) => {
promises.push(boxrec.getPersonById(cookieJar,data.id));
})
try {
const fighters = await Promise.all(promises);
fighters.forEach((fighter)=>{
boxer = JSON.parse(JSON.stringify(fighter.output));
fs.appendFile('C:\\Users\\User\\Documents\\newtest.csv',boxer, (err) => {
if (err) console.error('Could not append data to csv');
console.log('Data successfully appended');
})
});
} catch (e) {
console.log(e);
}
}
readsteam.destroy();
};
try {
writeData();
} catch (error) {
console.log("Error in writeData: " + error);
}