Nodejs file util

fileUtil.js

'use strict'

const Promise = require('bluebird');
const fs = Promise.promisifyAll(require('fs'));
const path = require('path');

/*
 * Bom headers are 3 Bytes binary
 */
const removeBom = filePath => {
    return fs.readFileAsync(filePath).then(buff => {
        if(buff[0].toString(16).toLowerCase() === 'ef' && buff[1].toString(16).toLowerCase() === 'bb' && buff[2].toString(16).toLowerCase() === 'bf'){
            console.log('%s has bom headers', filePath)
            buff = buff.slice(3)
            return fs.writeFileAsync(filePath, buff.toString(), 'utf8')
        }
        return
    })
}