FizzBuzz Sample Implementation

fizzbuzz.js

'use strict';

function parseNaturalNumber(number) {
  const currentNumVal = Number.parseInt(number, 10);
  if (!Number.isSafeInteger(currentNumVal) ||
    currentNumVal < 1) {
    return null;
  }

  return currentNumVal;
}

function fizzBuzzConverter(currentNum) {
  const currentNumVal = parseNaturalNumber(currentNum);
  if (!currentNumVal) {
    return;
  }

  const isMultp3 = (currentNum % 3) === 0;
  const isMultp5 = (currentNum % 5) === 0;

  if (!isMultp3 &&
    !isMultp5) {
    return `${currentNum}`;
  }

  let outputStr = '';

  if (isMultp3) {
    outputStr += 'Fizz';
  }

  if (isMultp5) {
    outputStr += 'Buzz';
  }

  return outputStr;
}

function processNumbers(limit) {
  const maxNum = parseNaturalNumber(limit);
  if (!maxNum) {
    return;
  }

  for (let i = 1; i <= maxNum; i += 1) {
    const outputStr = fizzBuzzConverter(i);
    if (outputStr) {
      console.log(outputStr);
    }
  }
}

module.exports = {
  parseNaturalNumber,
  fizzBuzzConverter,
  processNumbers
};