npm-package-resolver/libs/logger.js

An API for Resolving NPM package dependencies

/**
 * Created by liam on 28/08/2015.
 */


var winston = require('winston');
var _config = require('./config.js');
var _version = require('../package.json').version;
var logger;
var loggingEnabled = true;
var moment = require('moment');
var _ = require('underscore');
var config;




// current config file according to env production or dev
moment().format();


function setProductionLogging(){

    console.log('Logger set for PRODUCTION');
    // disabled normal logging/ allows warn and err
    loggingEnabled = false;
    config = _config.production;


    logger = new winston.Logger({
        transports: [
            new (winston.transports.Console)({
                json:true
            })
        ]
    });
    logger.on('error',function(e){
        logger.error('logger Error:'+e);
    });

    //logger.emitErrs = false;
}

function setDevLogging(){

    console.log('Logger set for DEVELOPMENT');
    loggingEnabled = true;
    config = _config.development;


    logger = new winston.Logger({
        transports: [
            new (winston.transports.Console)({
                json:true
            }),
            new (winston.transports.File)({
             filename: config.logsPath+'app.log',
             maxsize:10048576,maxFiles:10,json:true}
             )
        ]
    });
    logger.on('error',function(e){
        logger.error('logger Error:'+e);
    });


}



function loggerInstance(_origin) {
    var module = _origin


    this.log = function(){
        //arguments[0] = _room()+"-"+arguments[0];
        if (!loggingEnabled) {
            return;
        }
        logger.info.apply(this,generalLog.apply(this,arguments));
    }



    this.err = function(){
        var metaData = generalLog.apply(this,arguments)
        logger.error.apply(this,metaData);


    }


    this.warn = function() {
        logger.warn.apply(this,generalLog.apply(this,arguments));
    }

    var generalLog = function() {
        var args = Array.prototype.slice.call(arguments);
        //args[0] = _room()+"-"+args[0];

        var logObect = {
            'type':'resolver-log',
            'module':module,
            '@timestamp':moment().format('YYYY-MM-DDTHH:mm:ss.SSSZ'),
        };


        if (typeof args[args.length-1]=="object"){
            _.extend(logObect,args[args.length-1]);
            args[args.length-1] = logObect;
        } else {
            args.push(logObect);
        }
        //logger.info.apply(this,args);
        return args;

    }



}

/**
 * Prepares the log object to be sent into the logging function
 * @returns {Array} returns an array which should be treated as arguments
 */


function isProduction(){
    return process.env['NODE_ENV']=="production"?true:false;
}


module.exports = function returnLogger(originStr){

    console.log('Creating logger for origin:',originStr);

    if (!logger){
        console.log('Creating Singleton Logger Instance');
        if (isProduction()){
            setProductionLogging();
        } else {
            setDevLogging();
        }
    }

    return new loggerInstance(originStr);

}