Reverse each word in a sentence

main.js

/**
 * PROBLEM: Given a sentence reverse each word and print it back.
 * For example if the given sentence is "Mother India"
 * then output would be "rehtoM aidnI"
 * If given sentence is "hare-krishna hare-rama"
 * then output would be "erah-anhsirk erah-amar"
 */


// define a list by chars that we need to split the string with
// word bounderies are space, comma, colon, dash, semi colon
const split_by_chars = [' ', ',', ':', '-', ';', ''];

// define a function which will split the string with given string
// reverse it only if it is splitted by = ''
// call the same function recursively with next splitBy char in the sequence
// join the result
function splitReverseJoin(str, splitBy) {
  // if input param is not string 
  // or str is empty or single char
  // then end recursion
  if (typeof str !== 'string' || str.length === 0 || str.length === 1) {
    return str;
  }
  const splitted = str.split(splitBy);
  // when splitBy = '' that means no more splitting and all chars need to reversed
  if (splitBy === '') {
    return splitted.reverse().join('');
  }
  // otherwise get the nextSplitBy char from the sequence
  const nextSplitBy = split_by_chars[split_by_chars.findIndex((ch) => ch === splitBy) + 1];
  // call recursively with nextSplitBy for each splitted parts
  // join the result and return the value
  return splitted.map((part) => splitReverseJoin(part, nextSplitBy)).join(splitBy);
}

{
  const testStr = 'I am Chanchal';
  const expected = 'I ma lahcnahC';
  const actual = splitReverseJoin(testStr, ' ');

  console.log(actual === expected ? 'PASSED' : 'FAILED');
}

{
  const testStr = 'come, v cat,closer';
  const expected = 'emoc, v tac,resolc';
  const actual = splitReverseJoin(testStr, ' ');

  console.log(actual === expected ? 'PASSED' : 'FAILED');
}

{
  const testStr = 'mon-manush:matal';
  const expected = 'nom-hsunam:latam';
  const actual = splitReverseJoin(testStr, ' ');

  console.log(actual === expected ? 'PASSED' : 'FAILED');
}

{
  const testStr = 'dabanol-hati:ghora-gari dabanol-hati:ghora-gari';
  const expected = 'lonabad-itah:arohg-irag lonabad-itah:arohg-irag';
  const actual = splitReverseJoin(testStr, ' ');

  console.log(actual === expected ? 'PASSED' : 'FAILED');
}

{
    const testStr = 'Mother India';
    const expected = 'rehtoM aidnI';
    const actual = splitReverseJoin(testStr, ' ');
  
    console.log(actual === expected ? 'PASSED' : 'FAILED');
}

{
    const testStr = 'hare-krishna hare-rama';
    const expected = 'erah-anhsirk erah-amar';
    const actual = splitReverseJoin(testStr, ' ');
  
    console.log(actual === expected ? 'PASSED' : 'FAILED');
}