Script to change name of document to its size tag and save overwrite

I'm not 100% happy with the following code, however, it will have to do for now...

/*
Copy and Rename Files to Width and Height in CM.jsx
Version 1.0
Script to change name of document to its size tag and save overwrite
https://community.adobe.com/t5/photoshop/script-to-change-name-of-document-to-its-size-tag-and-save-overwrite/td-p/11736503

Files that produce duplicate filenames will be skipped, always check the count of input vs. output files!
*/

#target photoshop

// Save the current ruler units dialog display settings
var savedRuler = app.preferences.rulerUnits;
var savedDialogs = app.displayDialogs;

var inputFolder = Folder.selectDialog("Select the input folder to rename Photoshop compatible files:");
// Limit file format input
var inputFiles = inputFolder.getFiles(/\.(jpg|jpeg|tif|tiff|png|psd)$/i);

// Create the output folder
var renameFolder = Folder(inputFolder + "/Renamed");
if (!renameFolder.exists) {
    renameFolder.create();
}

app.displayDialogs = DialogModes.NO;

// Loop over the input files
for (var a = 0; a < inputFiles.length; a++) {
    try {
        open(inputFiles[a]);
        // Start doing stuff
        fileRenamer();
        // Finish doing stuff
    } catch (e) {
        continue;
    }
}

// Limit file format input
var outputFiles = renameFolder.getFiles(/\.(jpg|jpeg|tif|tiff|png|psd)$/i);
alert("SCRIPT COMPLETED:" + "\r" + "* " + inputFiles.length + " input files were found" + "\r" + "* " + outputFiles.length + " files were copied and renamed" + "\r" + "* Duplicate sized files have been skipped as they would have the same filename.");

// Restore the current ruler units dialog display settings
app.preferences.rulerUnits = savedRuler;
app.displayDialogs = savedDialogs;

function fileRenamer() {

    var aDoc = activeDocument;

    // PLACEHOLDER: Add XMP metadata code to capture the PreservedFileName before renaming!

    // Capture the filename extension
    var ext = aDoc.name.replace(/^.+(\.[^\.]+$)/, '$1');
    app.preferences.rulerUnits = Units.CM;
    var docWidth = aDoc.width.value;
    var docHeight = aDoc.height.value;
    // Round to 2 decimal places
    var docDimensions = (Math.round(docWidth * 100) / 100 + ' x ' + Math.round(docHeight * 100) / 100 + ' cm');
    // Copy, rename and close source doc
    File(aDoc.fullName).copy(renameFolder + "/" + docDimensions + ext);
    aDoc.close(SaveOptions.DONOTSAVECHANGES);
}

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

I have created the script for you, however, there are a number of points worth noting:

• There is no tag or reference to the width or height in CM or any other physical measurement unit, the native unit is pixels. In order to know the print size the resolution value will need to be correct to produce the print size
• It is not best-practice to have a full point/period character before the actual filename extension, as some software gets confused as what is the actual extension
• I agree with JJMack in that it is best to rename/copy to a new folder for safety. I also agree that Adobe Bridge is the better place to perform these types of operations than Photoshop (which is not to say that it can't be done in Photoshop)
• Adobe Bridge's Batch Rename can resize from metadata width/height, however, it uses the pixel value and not a physical measurement value
• Ideally there will be a graceful way to deal with multiple images that have the same print size. If multiple files are 10 x 15 cm in print size, only one of them can use that exact filename.

It sounds like you just need to rename the existing file not save a new file with the name you want then delete the old file. If you save over the file the filed name would not change. Save As with a new file name would  just create a second file with a different name. You can rename files  perhaps bridge has a rename feature that meets your requirements or a Bridge script could be created to rename the files with the names you want.  A Photoshop could also rename a document blacking file and close the open document without a save.  If you need to change the files content you would first need to save over the original file then do the file rename then close without a save.

IMO It would be best the save new file in a new folder then delete the old folder after you verify the new folder contains what you want.  Batch replacing files can be very destructive if somethings is not automated correctly.