Use js-beautify to reformat code in OS X 10.10 (Yosemite) Script Editor

tidyJSCode.applescript

// Ver 0.2
// Restores syntax highlighting by recompiling
// either restoring cursor or placing it at first error found


// Assumes installation of node.js 
// http://nodejs.org/download/
// with npm at:
var pathNPM = '/usr/local/bin';

// and js-beautify
// https://www.npmjs.com/package/js-beautify
// $ npm -g install js-beautify


function run() {
	"use strict";
	var appSE = new Application("Script Editor"),
		lstDoc = appSE.documents(),
		oDoc = lstDoc.length ? lstDoc[0] : null;

	if (!oDoc) return false;

	var drafts = { //
		getSelectedLineRange: function () {
			// works, but let me know if you see a shorter route :-)
			var rgxLFCR = /[\r\n]/,
				dct, strFull, iFrom, iTo, lngLast,
				varNoSeln = null;
			if (oDoc) {
				dct = oDoc.selection.characterRange();
				
				strFull = oDoc.text();
				if ((typeof strFull)[0] !== 's') return varNoSeln;
				lngLast = strFull.length - 1;

				iFrom = dct.x;
				iTo = dct.y - 1;
				
				if (iFrom < 0 || iTo < 0) return varNoSeln;
				
				if ((iFrom < lngLast) || (iTo < lngLast)) {
					while (iFrom--) {
						if (strFull[iFrom].match(rgxLFCR)) break;
					}
					iFrom += 1;

					while (iTo++ < lngLast)
						if (strFull[iTo].match(rgxLFCR)) break;

					return [iFrom, (iTo - iFrom)];
				} else return varNoSeln;
			}
		},
		setSelectedRange: function (iStart, iLength) {
			if (oDoc) {
				oDoc.selection = oDoc.text.characters.slice(iStart, iStart + iLength);
			}
		}
	};

	var app = Application.currentApplication(),
		lstSeln = drafts.getSelectedLineRange();


	app.includeStandardAdditions = true;


	app.setTheClipboardTo(
		oDoc.text().replace(/\r/g, '\n')
	);

	oDoc.text = app.doShellScript(
		'export PATH=$PATH:' + pathNPM +
		'; pbpaste | js-beautify -f - -t -j --good-stuff -p -n -w 80'
	);

	// Either restore selection or select first syntax error
	if (appSE.compile(oDoc)) {
		if (lstSeln)
			drafts.setSelectedRange(lstSeln[0], lstSeln[1]);
	} else appSE.checkSyntax(oDoc);
}