macOS JXA script to convert word files (docx) to pdf. Change the file to executable `chmod 777 ./convertWordFile2PDF.js` and run it by `./convertWordFile2PDF.js`.

convertWordFile2PDF.js

#!/usr/bin/env osascript -l JavaScript

/*
 * [resource](https://github.com/JXA-Cookbook/JXA-Cookbook/wiki)
 */

const app = Application.currentApplication();

// allow to use `chooseFile` and `chooseFolder` methods
app.includeStandardAdditions = true;

const filePaths = app.chooseFile({
  withPrompt: "Pick docx files for converting to PDF",
  multipleSelectionsAllowed: true,
});

const outputFolder = app.chooseFolder({
  withPrompt: "Pick the location to store the PDFs",
});

const word = Application("Microsoft Word");

filePaths.forEach((filePath) => {
  const { isWordDocument, fileName } = getFileName(filePath, outputFolder);

  if (!isWordDocument) {
    console.log(`${filePath} is not a word document.`);
    return;
  }

  // The `open` method didn't return document, using `activeDocument` instead.
  word.open(filePath);
  const doc = word.activeDocument;

  word.saveAs(doc, {
    fileName,
    fileFormat: "format PDF",
  });

  doc.close({ saving: "no" });
});

function getFileName(filePath, outputFolder) {
  const wordExtRe = /(\.docx|\.doc)$/;
  const inputPath = filePath.toString();
  const found = inputPath.match(wordExtRe);
  const filename = inputPath.split("/").pop().replace(wordExtRe, ".pdf");
  const fileName = `${outputFolder}/${filename}`;
  return {
    isWordDocument: Boolean(found),
    fileName,
  };
}