Updated Factory Function Setup

file-reader-factory.js

function fileReader(fs, logger) {
    function readAFile(filepath) {
        try {
            return fs.readFileSync(filePath, { encoding: 'utf8' });
        } catch (e) {
            logger.log(e.message);
            return null;
        }
    }

    return {
        readAFile: readAFile
    };
}

module.exports = fileReader;

logger-factory.js

'use strict';

let singletonLogger = null;

function logger(loggerFactory) {
    return singletonLogger === null ? loggerFactory.create() : singletonLogger;
}

module.exports = logger;