Check if a string is entirely made of the same substring JavaScript

We are required to write a JavaScript function that takes in a string. It should return true or false based on whether the input consists of a repeated character sequence.

The length of the given string is always greater than 1 and the character sequence must have at least one repetition.

For example −

• "aa" should return true because it entirely contains two strings "a"
• "aaa" should return true because it entirely contains three string "a"
• "abcabcabc" should return true because it entirely containas three strings "abc"
• "aba" should return false because it at least there should be two same substrings and nothing more
• "ababa" should return false because "ab" exists twice but "a" is extra so false

Example

const checkCombination = (str = '') => {
   if( str.length==1 ) {
      return true;
   };
   for(let i = 1; i <= str.length / 2; i++){
      if(str.length % i !== 0){
         continue;
      }
      const sub = str.substring(0, i);
      if(isRepeating(sub, str)){
         return true;
      };
   };
   return false;
}
const isRepeating = (sub, str) => {
   if(str.length > sub.length){
      let left = str.substring(0,sub.length);
      let right = str.substring(sub.length, str.length);
      return left===sub && isRepeating(sub,right);
   };
   return str === sub;
}
console.log(checkCombination('aa'));
console.log(checkCombination('aaa'));
console.log(checkCombination('abcabcabc'));
console.log(checkCombination('aba'));
console.log(checkCombination('ababa'));

Output

This will produce the following output −

true
true
true
false
false