Sample problem to upgrade software version

upgradeVersion.js

/*
We want to upgrade from initialVersion to targetVersion. To do this 
we run through these steps:
- First, we need one upgrade for each incremental major version 
(resetting the other numbers to 0)
- Next, we need one upgrade for each incremental minor version 
(resetting the third and fourth numbers, if applicable, to 0)
- Then, we need a one-time upgrade to the target third number 
(if applicable)
- Finally, we need a one-time upgrade to the target fourth number 
(if applicable)
Write a function updateVersion that returns an array of strings 
containing all the intermediate versions, including the initial 
version and the target version, in order of upgrade. 

Examples:
- To upgrade a merchant from 2.1 to 3.2, we need to do:
2.1 → 3.0 → 3.1 → 3.2

- To upgrade a merchant from 3.3.2 to 4.2.7, we need to do:
3.3.2 → 4.0.0 → 4.1.0 → 4.2.0 → 4.2.7

- To upgrade a merchant from 4.1.3.56 to 6.2.3.170, 
we need to upgrade as follows:
4.1.3.56 → 5.0.0.0 → 6.0.0.0 → 6.1.0.0 → 6.2.0.0 → 6.2.3.0 → 6.2.3.170
*/


// Pseudocode
// - result = []
// - add input to result (result = ["2.1"])
// - split the input into an array
// - up the major version to target major version
//   - if array[0] != finalVersion[0] -> array[0]+=1
//   - while the major version is less than or equal to target, increment it and add with zeros to list
  
// - update minor version with same process
// - update subminor version with same process
// - update subsubminor version with same process

console.log(upgradeVersion('4.1.3.56', '6.2.3.170'));

function upgradeVersion(initialVersion, targetVersion) {
  let output = [initialVersion];
  let currVersion = "";
  const iv = initialVersion.split('.');
  const tv = targetVersion.split('.');
  const versionLength = iv.length;
  
  for (let i = 0; i < versionLength; i++){
    
      if (i > 1) {
        iv[i] = tv[i];
        const versionString = iv.fill(0, i + 1).join('.');
        
        output.push(versionString);
      }
      
      while(iv[i] < tv[i]) {
        iv[i] = parseInt(iv[i]) + 1;
        const versionString = iv.fill(0, i + 1).join('.')
        output.push(versionString);
      }
  }

  
  return output;
}