NodeJs crypto secure random choice from string or Array

index.ts

import { randomBytes } from 'crypto';

let bitsNeeded: number, bytesNeeded: number, chunks: number, tooBig: number, randomNumber: number, index: number;
export function randomChoiceFromIndexable(indexable: string | any[]) {
    bitsNeeded = Math.log2(indexable.length);
    bytesNeeded = Math.ceil(bitsNeeded / 8);
    chunks = Math.floor(256 / indexable.length) || 1;
    tooBig = indexable.length * chunks;
    do {
        randomNumber = randomBytes(bytesNeeded).readUIntBE(0, bytesNeeded);
    } while (randomNumber >= tooBig);
    index = randomNumber % indexable.length;
    return indexable[index];
}