server.js

var port = process.env.PORT || 1337;
var baseHost = process.env.WEBSITE_HOSTNAME || 'localhost';

var http = require('http');
var express = require('express');
var bodyParser = require('body-parser');
var vm = require('vm');

var app = express();

var server = http.createServer(app);

var jsonParser = bodyParser.json();

function executionHandler(isTrigger){
	return function(req,res){
	if(!req.body || !req.body.script){
		console.log('The request failed because it was missing the code:\n' + JSON.stringify(req.body));
		return res.status(400).send('You need to provide a string of JavaScript code to execute.');
	}
	
	
	try{
		var sandbox = req.body.context ? req.body.context : {};
		
		var code = "function code(){\n" +  req.body.script + "\n}\n 	var result = code();";
		try{
			vm.runInNewContext(code, sandbox);
			if (isTrigger && !sandbox.result){
				return res.status(202).send(sandbox.result);
			}						
		}catch(error){
			console.log('The execution of the JavaScript code:\n' + req.body.script + '\nAnd Context:\n' +  JSON.stringify(req.body.context) + '\nFailed with error:\n' + error);
			return res.status(400).send('The code you provided has an error in it. You must provide vaid JavaScript code that only references data in the sandbox.\n\n' + error);
		}
		res.json(sandbox.result);

	}catch(error){
			console.log('The execution of the JavaScript code:\n' + req.body.script + '\nAnd Context:\n' +  JSON.stringify(req.body.context) + '\nFailed with error:\n' + error);
			return res.status(400).send('Was not able to process the response from the JavaScript code you provided.\n\n' + error);
		
	}
};
}

app.post('/Execute', jsonParser,  executionHandler(false));

app.post('/ExecutePollTrigger', jsonParser, executionHandler(true));

app.get('/swagger/docs/v1', function(req,res){
	var fs = require('fs');
	var object = JSON.parse(fs.readFileSync('api.json','utf8'));
	res.json(object);
});

server.listen(port, baseHost, function () {
    console.log("Server started ... http://%s:%s",server.address().address,server.address().port);
});