Replace fonts in all the Illustrator files in a folder

replace_fonts.jsx

/*
Replace fonts in all the Illustrator files in a folder
Edit the array at the top to your own substitutions
Find the font names to replace using: https://gist.github.com/2778294
*/

// fonts to replace
var substitutions = [
  ['BellGothic BT', 'Bold',         'Roboto', 'Condensed'],
  ['BellGothic Blk BT', 'Black',    'Roboto', 'Bold Condensed'],
];

//  turn the substitutions into real fonts
var subsRight = [];
var fontCount = textFonts.length;
var subsCount = substitutions.length;
for (var i = 0; i < fontCount; i++) {
  var font = textFonts[i];
  for (var j = 0; j < subsCount; j++) {
    if (substitutions[j][2] == font.family && substitutions[j][3] == font.style) {
      subsRight[j] = font;
    }
  }
}

function getAllFiles(folder) {
  var fileList = [];
  function recurse (folder) {
    var files = folder.getFiles("*.ai");
    for (var i = 0; i < files.length; i++)
      fileList.push(files[i]);

    var folders = folder.getFiles();
    var len = folders.length;
    for (var i = 0; i < len; i++) {
      if (folders[i] instanceof Folder) {
        recurse(folders[i]);
      }
    }
  }
  if (folder != null && folder instanceof Folder)
    recurse(folder);
  return fileList;
}

var sourceFolder = Folder.myDocuments.selectDlg( 'Select the folder with Illustrator files in which you want to replace fonts');
var files = getAllFiles(sourceFolder);

for ( var i = 0; i < files.length; i++ ) {
  var file = files[i];
  var doc = app.open(file);

  // replace the font
  var frames = doc.textFrames;
  for ( var j = 0; j < frames.length; j++ ) {
    var ranges = frames[j].textRanges;
    for ( var k = 0; k < ranges.length; k++ ) {
      var range = ranges[k];
      for (var f = 0; f < subsCount; f++) {
        if (range.characterAttributes.textFont.family == substitutions[f][0] 
          && range.characterAttributes.textFont.style == substitutions[f][1]) {
          range.characterAttributes.textFont = subsRight[f];
        }
      }
    }
  }
  redraw();

  doc.save();
  doc.close();  
}

Thanks Marcus, I was able to make both works in CC2020. This one an the other you pointed me to.
I don’t know if the is my missing font, but it will not replace it.

The script to get his name when missing give me:
It’s name is «SolidEdgeISOCE» with no style.
In character panel when missing:
It’s name is «SolidEdgeISOCE» with Style «Normal»
In character panel and with script when available:
It’s name is «Solid Edge ISO CE» with Style «Regular».

Both script with any combinaison of name/style can’t find/replace that missing font.