random-string.js

import { randomBytes } from 'crypto';

const charset =  'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';

const randomString = (length) => {
	return new Promise((resolve, reject) => {
		const chars = new Array(length);

		randomBytes(length, (error, bytes) => {
			if (error) {
				return reject(error);
			}

			for (let i = 0; i < length; i++) {
				chars[i] = charset[bytes[i] % charset.length];
			}

			resolve(chars.join(''));
		});
	});
};

To use:

import { randomString } from './random-string';

// Get a random, 8 character ID
randomString(8);