generatepass.js

// Dependencies
const Enumerable = require ('linq');

// Constants
const UPPER_CASE_CHARS = `ABCDEFGHIJKLMNOPQRSTUVWXYZ`;
const LOWER_CASE_CHARS = `abcdefghijklmnopqrstuvwxyz`;
const DIGITS = `0123456789`;
const SPECIAL_CHARS = `!@#$%^&*+=?/\\_`;
const VALID_CHARACTERS =
	UPPER_CASE_CHARS + LOWER_CASE_CHARS +
	DIGITS + SPECIAL_CHARS;
const LENGTH = 16;

// Generate
const pass = Enumerable
	.range (0, LENGTH)
	.select (() => Math.random () * VALID_CHARACTERS.length)
	.select (r => Math.floor (r))
	.select (r => VALID_CHARACTERS [r])
	.toArray ()
	.join ('');

// Done
console.log (pass);