Child logger loses its transports when added to `winston.loggers`

So I’m starting to use winston after transferring from python to JS. I am used to child loggers from logging and so I tried to do the same with winston.

Here is my config:

import winston from 'winston';

const base_logger = winston.create({
    level: 'info',
    format: winston.format.json(),
    transports: [
        new winston.transports.Console({}),
    ]
});

const child = base_logger.child({});
console.log(child.transports);  // working perfectly, has the console transport
winston.loggers.add('child', child);
console.log(winston.loggers.get('child'). transports); // doesn't work, shows an empty array

I will debug the code to try to find the problem, but I am about 90% sure I am using winston wrong.

[kouhin]

I think this is a bug of winston.Container.

You can simply confirm this issue by following code:

const consoleTransport = new winston.transports.Console();
const log = new winston.Container({
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.simple()
  ),
  transports: [consoleTransport],
});

log.add('test1', {
  level: 'warn',
});

log.add('test2', {
  level: 'info',
});

const log1 = log.get('test1');
const log2 = log.get('test2');

// You can see both log1 and log2 are set to 'warn'

log1.info('[info] log1');
log1.warn('[warn] log1');
log2.info('[info] log2');
log2.warn('[warn] log2');

// This is the reason
console.info(consoleTransport.parent === log1, consoleTransport.parent === log2);
// Output: true false

[robross0606]

I just ran into this as well. I wanted to have a default logger, and then spin off child loggers that are named. It don’t see how this is possible with the current API.