Script that finds specific text and change base from filename

/*
  Batch search for a TextFrame of a given size and replace its contents with the file name
  Discussion: https://community.adobe.com/t5/illustrator-discussions/script-that-finds-specific-text-and-change-base-from-filename/m-p/13365933#M344679
  Author: Sergey Osokin, email: hi@sergosokin.ru
  Check other scripts: https://github.com/creold
*/

//@target illustrator
app.preferences.setBooleanPreference('ShowExternalJSXWarning', false); // Fix drag and drop a .jsx file

// Main function
function main() {
  var size = 4; // pt
  var dir = Folder.selectDialog('Select the source folder...');
  if (dir !== null) {
    var files = getAllFiles(decodeURI(dir), '.ai');
    for (var i = 0, len = files.length; i < len; i++) {
      changeText(files[i], size);
    }
  }
}

function getAllFiles(dir, ext) {
  var fList = Folder(dir).getFiles(),
      files = [];
    for (var i = 0, len = fList.length; i < len; i++) {
    if (fList[i] instanceof Folder) {
      files = files.concat(getAllFiles(fList[i], ext));
    } else if (fList[i] instanceof File) {
      if (fList[i].name.indexOf(ext) > -1) {
        files.push(fList[i]);
      }
    }
  }
  return files;
}

function changeText(f, size) {
  var doc = app.open(f);
  var docName = doc.name.replace(/\.[^\.]+$/, '');
  var tf = doc.textFrames;
  for (var i = 0, len = tf.length; i < len; i++) {
    if (tf[i].textRange.characterAttributes.size == size) {
      tf[i].contents = docName;
    }
  }
  doc.save();
  doc.close();
}

// Run script
try {
  main();
} catch (e) {}