JSFiddle - React, Tailwind, and code Playground

JavaScript

const callbackHell = (fileArray, hashFileAsyncFn, writeToBDAsyncFn) => {
  const hashes = [];
  const hashAlternately = (headFile, tailFiles) => {
    if (!head) writeToBDAsyncFn(hash, (err, result) => {
        if (err) {
          console.log(e);
          return;
        }
        console.log('Hashes are written');
    });
    
    hashFileAsyncFn(head, hash => {
      hashes.push(hash);
      hashAlternately(tailFiles[0], tailFiles.slice(1));
    });
 }
 
 hashAlternately(fileArray[0], fileArray.slice(1));
}