'use strict';
const fileType = require('file-type');
const exts = new Set([
'7z',
'bz2',
'gz',
'rar',
'tar',
'zip',
'xz',
'gz'
]);
module.exports = input => {
const ret = fileType(input);
return exts.has(ret && ret.ext) ? ret : null;
};