Middleware para log para Node

gistfile1.txt

const createLogger = require('winston').createLogger;
const format = require('winston').format;
const transports = require('winston').transports;

const logger = createLogger({
    level: 'error',
    format: format.json,
    transports: [
        new transports.File({
            filename: "logs/error.json",
        })
    ]
});


if (process.env.NODE_ENV !== 'production')
    logger.add(new transports.Console({
        format: format.simple()
    }))