logger.js

const winston = require("winston");
winston.emitErrs = true;

let transports = [];

if (process.env.LOGS === "DEV") {
    transports.push(
        new winston.transports.Console({
            handleExceptions: true,
            json: false,
            colorize: true
        })
    );
} else if (process.env.LOGS === "ALL_FILES") {
    transports.push(
        new winston.transports.File({
            filename: "./logs/all.log",
            level: "debug",
            handleExceptions: true,
            json: true,
            maxsize: 5242880,
            maxFiles: 3,
            colorize: false,
            timestamp: function() {
                //5MB
                return new Date().toISOString();
            }
        })
    );
} else {
    transports.push(
        new winston.transports.File({
            name: "error-file",
            level: "error",
            filename: "./logs/error.log",
            handleExceptions: true,
            json: true,
            maxsize: 5242880, //5MB
            maxFiles: 3,
            colorize: false,
            timestamp: function() {
                return new Date().toISOString();
            }
        })
    );

    transports.push(
        new winston.transports.File({
            name: "warning-file",
            level: "warn",
            filename: "./logs/warning.log",
            handleExceptions: true,
            json: true,
            maxsize: 5242880, //5MB
            maxFiles: 3,
            colorize: false,
            timestamp: function() {
                return new Date().toISOString();
            }
        })
    );
}

const logger = new winston.Logger({
    transports,
    exitOnError: false
});

logger.stream = {
    write: function(message, encoding) {
        logger.info(message);
    }
};

module.exports = logger;