How to Add Constraint With No Validation?

Kata - converting strings into different case types - can solve for single case type but not double - please help :)

Harris

This is the current output:

thisIsAString ThisIsAString this_is_a_string this-is-a-string This Is A String thIs Is A strIng THiS iS a STRiNG Error

Looking for suggestions on how to evaluate with 2 case types. Been staring at this for hours and can't solve it. I imagine there are simpler ways to write this entire Kata, but I'm just starting with coding and don't have all the tools/skills yet to pull from. Would appreciate addressing my long drawn out solution instead of rewriting the entire thing.

Thanks for any help!

 const makeCase = function(input, style) {
  let result = '';
  let styleTypes = []; 
  if (typeof style === 'string') {
    styleTypes.push(style); 
  } else if (typeof style !== 'string') {
    for (let i = 0; i < style.length; i++) {
      styleTypes.push(style[i]);
    }
  } 
  for (let i = 0; i < styleTypes.length; i++) {
    if (style === 'camel') {
      result = camelCase(input);
    } else if (style === 'pascal') {
      result = pascalCase(input);
    } else if (style === 'snake') {
      result = snakeCase(input);
    } else if (style === 'kebab') {
      result = kebabCase(input);
    } else if (style === 'title') {
      result = titleCase(input);
    } else if (style === 'vowel') {
      result = vowelCase(input);
    } else if (style === 'consonant') {
      result = consonantCase(input);
    } else if (style === 'upper') {
      result = upperCase(input);
    } else if (style === 'lower') {
      result = lowerCase(input);
    } else {
      result = 'Error';
    }
  }
  return result;
}

const camelCase = function(string) {
  let newString = '';
  for (i = 0; i < string.length; i++) {
    if (string[i] === ' ') {
      i++;
      newString += string[i].toUpperCase();
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const pascalCase = function(string) {
  let newString = '';
  for (i = 0; i < string.length; i++) {
    if (i === 0) {
      newString += string[0].toUpperCase();
    } else if (string[i] === ' ') {
      i++;
      newString += string[i].toUpperCase();
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const snakeCase = function(string) {
  let newString = ''; 
  for (i = 0; i < string.length; i++) {
    if (string[i] === ' ') {
      newString += '_';
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const kebabCase = function(string) {
  let newString = '';
  for (let i = 0; i < string.length; i++) {
    if (string[i] === ' ') {
      newString += '-';
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const titleCase = function(string) {
  let newString = ''; 
  string.toLowerCase();
  for (let i = 0; i < string.length; i++) {
    if (i === 0) {
      newString += string[i].toUpperCase();
    } else if (string[i] === ' ') {
      newString += ' ' + string[i + 1].toUpperCase();
      i++;
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const vowelCase = function(string) {
  let newString = '';
  for (let i = 0; i < string.length; i++) {
    if (string[i] === 'a' || 
        string[i] === 'e' || 
        string[i] === 'i' || 
        string[i] === 'o' || 
        string[i] === 'u' ) {
       newString += string[i].toUpperCase();   
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const consonantCase = function(string) {
  let newString = '';
  for (let i = 0; i < string.length; i++) {
    if (string[i] !== 'a' && 
        string[i] !== 'e' && 
        string[i] !== 'i' && 
        string[i] !== 'o' && 
        string[i] !== 'u' ) {
       newString += string[i].toUpperCase();   
    } else {
      newString += string[i];
    }
  }
  return newString;
}

const upperCase = function(string) {
  let newString = '';
  newString = string.toUpperCase();
  return newString;
}

const lowerCase = function(string) {
  let newString = '';
  newString = string.toLowerCase();
  return newString;
}

//Test console logs for each function
// console.log(camelCase('this is a string'));
// console.log(pascalCase('this is a string'));
// console.log(snakeCase('this is a string'));
// console.log(kebabCase('this is a string'));
// console.log(titleCase('this is a string'));
// console.log(vowelCase('this is a string'));
// console.log(consonantCase('this is a string'));
// console.log(upperCase('this is a string'));
// console.log(lowerCase('this is a string'));

//Console logs for expected result
console.log(makeCase("this is a string", "camel"));
console.log(makeCase("this is a string", "pascal"));
console.log(makeCase("this is a string", "snake"));
console.log(makeCase("this is a string", "kebab"));
console.log(makeCase("this is a string", "title"));
console.log(makeCase("this is a string", "vowel"));
console.log(makeCase("this is a string", "consonant"));
console.log(makeCase("this is a string", ["upper", "snake"]));

//Expected output
// thisIsAString
// ThisIsAString
// this_is_a_string
// this-is-a-string
// This Is A String
// thIs Is A strIng
// THiS iS a STRiNG
// THIS_IS_A_STRING