Example of logging to a file in Node

foo.js

import logger from ‘./logger’;

function foo {
	try {
		// do something
		logger.log('Victory in foo!');
	} catch (error) {
		logger.error(`Foo failed. Error: $(error)`);
	}
}

logger.js

import fs from 'fs';
import { Console } from 'console';

const filename = (new Date).toISOString().split('T')[0];
const infoLog = filename + '-log.log';
const errorLog = filename + '-error.log';

// test if files exist, and create them if they don't

const output = fs.createWriteStream(infoLog);
const errorOutput = fs.createWriteStream(errorLog);
const logger = new Console({ stdout: output, stderr: errorOutput });

export default logger;