res.download(NodeJS) not triggering a download on the browser - node.js

Question

I've been struggling with this for a while and can't seem to find an answer, I'm developing a website with a budgeting option, I'm sending an object from the client to the server, and that server is using PDFKit to create a PDF version of the budget, once it's created I want to actually send back that PDF to the client and trigger a download, this is what I've done
Client-side code:
let data = {
nombre: this.state.name,
email: this.state.email,
telefono: this.state.phone,
carrito: this.props.budget.cart,
subTotal: this.props.budget.subTotal,
IVA: this.props.budget.tax,
total: this.props.budget.subTotal + this.props.budget.tax
}
axios({
method: 'post',
url: 'http://localhost:1337/api/budget',
data: data
})
.then((response) => {
console.log('This is the response', response);
window.open('/download')
})
.catch((error) => {
alert(error);
})
So that data goes to my server-side code perfectly and it looks like this
const pdf = require('pdfkit');
const fs = require('fs');
const path = require('path');
exports.makePDFBudget = (req, res) => {
let myDoc = new pdf;
myDoc.pipe(fs.createWriteStream(`PDFkit/budget.pdf`));
myDoc.font('Times-Roman')
.fontSize(12)
.text(`${req.body.name} ${req.body.phone} ${req.body.email} ${req.body.cart} ${req.body.subTotal} ${req.body.total} ${req.body.tax}`);
myDoc.end()
}
That's creating my PDF, what I want now is that once it's created and the response is sent back to the client, the client opens a new window with the URL "/download" which is set to download that PDF, but that's not happening for some reason, it opens up the new window but the download never starts and it throws absolutely no error I'm my Node console or browser console
this is how I send my file to the client
const fs = require('fs');
const path = require('path');
exports.downloadPDFBudget = (req, res) => {
res.download(__dirname + 'budget.pdf', 'budget.pdf');
}
And this is how my server index looks like
const bodyParser = require('body-parser');
const express = require('express');
const app = express();
const api = express.Router();
const { makePDFBudget } = require('./PDFkit/makePDFBudget.js');
const { downloadPDFBudget } = require('./PDFkit/downloadPDFBudget.js')
app.use(express.static(__dirname + '/../public'));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json({extended: true}));
api.route('/budget')
.post(makePDFBudget)
api.route('/download')
.get(downloadPDFBudget)
app.use('/api', api);
const port = 1337;
app.listen(port);
console.log('Listening on port ', port);
module.exports = app;

Answer 1

I just solved it, the port in which I was running my client obviously was different from the one I was running my server, so I had to open a window to my server's port to trigger the download, I realized this because I threw a console log on the function that was supposed to do the res.download it wasn't showing up. Thanks!

Answer 2

I guess the main problem here:
res.download(__dirname + 'budget.jpg', 'budget.pdf');
Make a correct file name. Your file is pdf, not jpg.
At this code res.end(Buffer.from('budget.pdf')) you sending string, not file content. But headers like you want to send a file.
The last. Your application designed like you will have only one user. Could you add userId to file names? Or use DB for storing data and generate pdf on request without storing a file to the file system.