File uploading validations for MIME

upload-file-validations.js

const util = require('util');
const FileType = require('file-type');
var mmm = require('mmmagic'),
    Magic = mmm.Magic;
var magic = new Magic(mmm.MAGIC_MIME_TYPE);
const exec =  util.promisify(require('child_process').exec);
(async () => {
    console.log('FileType csv', await FileType.fromFile('/path/to/file-name.csv'));
    console.log('FileType png', await FileType.fromFile('/path/to/file-name.png'));
    magic.detectFile('/path/to/file-name.csv', (err, res) => 
        console.log('magic csv', res)
    )
    magic.detectFile('/path/to/file-name.png', (err, res) => 
        console.log('magic csv', res)
    )
    console.log('file csv', await exec('file --mime-type /path/to/file-name.csv | grep -oh  "[a-z]*/[a-z]*$"', { shell: true }));
    console.log('file png', await exec('file --mime-type /path/to/file-png | grep -oh  "[a-z]*/[a-z]*$"', { shell: true }));
})().catch(console.error);