How to force nodejs winston log to file before process exit

Question

I am using winston 3 to log my data. But sometimes it didn't log the error before process exit.

The following process will exit, without log to the logfile.log:

const winston = require('winston');

winston.add(new winston.transports.File({
    filename: 'logfile.log'
}));

winston.info('please log me in');
process.exit(1);

One of attempted solution is used callback:

const winston = require('winston');

const logger = new winston.createLogger({
    new winston.transports.File({
    filename: 'logfile.log'
}));

winston.info('please log me in', () => {
    process.exit(1);
});

setTimeout(() => {}, 100000000000); // pause the process until process.exit is call

But Winston 3.x have callback issue, so the above code won't work, the process will not exit.

I am looking for a workable solution? Any help will be greatly appreciated. My OS is Ubuntu 16.04, Node 10.17.

Edit 1: I also have try Prabhjot Singh Kainth's suggestion use finish event to trigger process exit:

const winston = require('winston');

const logger = winston.createLogger({
    transports: [
        new winston.transports.File({
            filename: 'logfile.log'
        })
    ]
});

logger.info('please log me in');

logger.on('finish', () => {
    process.exit();
});
logger.end();

setTimeout(() => {}, 100000000000); // pause the process until process.exit is call

In the above case, the process will exit, but no log file will be created.

Answer 1

Finally, I find a workable solution. Instead of listening to logger finish event, it should listen to file._dest finish event. But file._dest is only created after file open event. So it need to wait for file open event in initialization process.

const winston = require('winston');

const file = new winston.transports.File({
  filename: 'logfile.log'
});

const logger = winston.createLogger({
    transports: [file]
});

file.on('open', () => {  // wait until file._dest is ready
  logger.info('please log me in');
  logger.error('logging error message');
  logger.warn('logging warning message');

  file._dest.on('finish', () => {
    process.exit();
  });
  logger.end();
});

setTimeout(() => {}, 100000000000); // pause the process until process.exit is call

Answer 2

How about this one?

logger.info('First message...')
logger.info('Last message', () => process.exit(1))