deep-random-pick/src/arraypick.ts

Picks a pseudo-random item from a pool in several ways, including a recursive method that allows for more control over probability.

var Alea = require('alea');

export const arrayPick = (array: any[]) => {
    if (array) {
        if (Array.isArray(array)) {
            const prng = new Alea();
            if (array.length < 1 || !array) {
                return null;
            } else if (array.length === 1) {
                return array[0];
            } else {
                return array[Math.round(prng() * (array.length - 1))];
            }
        } else {
            return array;
        }
    } else {
        return null;
    }
}