Node.js script to dedupe a JSON-compliant array

dedupe.js

/**
 * Node script to dedupe an array in a file.
 *
 * Prereqs: lodash (globally)
 *
 * Use:
 * > node dedupe.js path/to/file.js [path/to/newfile.js]
 */

var fs = require('fs'),
    _  = require('/usr/local/lib/node_modules/lodash'),
    file = process.cwd() + '/' + process.argv[2],
    fileNew = process.argv[3] || file;

console.log('Reading \'' + file + '\'');

fs.readFile(file, 'utf8', function (err, data) {
  var usableData = JSON.parse(data),
      deduped    = _.uniq(usableData, true);

  writeFile(deduped);

});

function writeFile(deduped) {
  console.log('Writing file ' + fileNew);

  fs.writeFile(fileNew, JSON.stringify(deduped), function (err) {
    if (err) throw err;
    console.log('Saved ' + fileNew);
  });
}