Exit process when pipe finish - node.js

Question

I'm trying to import users from a CSV file with node.js in CLI.
But I don't know how to exit program properly when all the tasks are completed.
Here my code using Sails.js and node-csv
"use strict";
const Sails = require('sails');
const fs = require('fs');
const csv = require('csv');
const filename = './test.csv';
Sails.load({
models : { migrate : 'safe'},
log : { level : 'info' },
hooks : { grunt : false, sockets : false, pubsub : false },
}, (errSails, sails) => {
if ( errSails ) process.exit(1);
let input = fs.createReadStream(filename);
let parser = csv.parse();
let transformer = csv.transform( (record) => {
sails.log.debug('record : ', record);
sails.log.info('Transformer : searching user...');
return User.findOne({email: record.email})
.then( (user) => {
sails.log.info('Transformer : search complete');
if ( !user ) {
sails.log.info('Transformer : no users found');
return User.create(record);
}
return record;
})
.catch( (err) => sails.log.error(err) );
});
parser
.on('readable', () => sails.log.info('Parser readable'))
.on('finish', () => sails.log.info('Parser finish'))
.on('error', (err) => sails.log.error('Parser error : ', err));
transformer
.on('finish', () => sails.log.info('Transformer finish'))
.on('error', (err) => sails.log.error('Transformer error : ', err));
input.pipe(parser).pipe(transformer).pipe(process.stdout);
//--- Exit program
// process.exit();
});
Here is what is inside the terminal
debug: record : { ... }
info: Transformer : searching user...
info: Parser readable
info: Parser finish
info: Transformer finish
info: Transformer : search complete
info: Transformer : no users found
Without process.exit();, the program continue forever.
If I uncomment the process.exit(); line, the program terminate immediately without parsing anything. But, if I put this line into the finish event of the transformer, the program exit after info: Transformer finish without the last two lines.
I want to know how and where I should put process.exit(); to exit program to be sure that all users of my CSV file are created in the database.

Answer 1

First, don't try to user Process exit on error happening, use throws new Error. read more here.
and about your problem: the second thing you have an async function and put your exit program command out of async function body, so it makes your second problem, for your first problem, to make exit when everything will be done, you should change your async function first.to something like this:
.on('finish', () => {sails.log.info('Transformer finish');process.exit(1);})