is-zip 
Check if a Buffer/Uint8Array is a ZIP file
Install
$ npm install --save is-zip
Usage
var isZip = require('is-zip');
var read = require('fs').readFileSync;
isZip(read('foo.zip'));
// => true
Check if a Buffer/Uint8Array is a ZIP file
$ npm install --save is-zip
var isZip = require('is-zip');
var read = require('fs').readFileSync;
isZip(read('foo.zip'));
// => true