JavaScript - Password generator based on crypto.getRandomValues()

PasswordGenerator.js

class PasswordGenerator {
  
  #chunksFromString(string, chunkSize) {
    const numChunks = Math.floor(string.length / chunkSize);
    const chunks = new Array(numChunks);
    
    for (let i=0, o=0; i < numChunks; ++i, o+=chunkSize) {
      chunks[i] = string.substr(o, chunkSize);
    }
    return chunks;
  }
  
  // we use an alphabet of 73 symbols
  // log2(73) ≈ 6.19, 64/log2(73) ≈ 10.34
  // so from a BigUint64 we can generate at most 
  // ten random symbols
  #alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+-_!$;@*?^|";
  #symbolsCount = 73n;
  #charsPerBigUint64 = 10;
  
  #generateEntropy(length) {
    const array = new BigUint64Array(Math.ceil(length/this.#charsPerBigUint64));
    crypto.getRandomValues(array);
    return array;
  }
  
  *#charsFromBigUint(biguint) {
    for (let c=0; c<this.#charsPerBigUint64; c++) {
      yield this.#alphabet[biguint % this.#symbolsCount];
      biguint /= this.#symbolsCount;
    }
  }
  #stringFromBigUint(biguint) {
    return [...this.#charsFromBigUint(biguint)].join('');
  }

  generate(length, n=1) {
    const totalLength = n*length;
    const array = this.#generateEntropy(totalLength);
    let password = '';
    for(let i=0; i<array.length && password.length<(totalLength); ++i) {
      password += this.#stringFromBigUint(array[i]);
    }
    if (n === 1) {
      return password.substr(0, length);
    }
    return this.#chunksFromString(password, length);
  }
}

const gen = new PasswordGenerator();
// generate 5 passwords of length 15
passwords = gen.generate(15,5);
console.log(passwords);