依赖request模块

test.js

var util = require('util'),
    vm = require('vm'),
    fs = require('fs');

vm.runInNewContext(fs.readFileSync('user.js'), {
	requestUrl: requestUrl
}, 'myfile.vm');

function requestUrl(url, callback) {
	require('request')(url, function (error, response, body) {
	  if (!error && response.statusCode == 200) {
	  	var data = JSON.parse(body);
		callback(data);
		//TODO
		console.log('complete, and data.test=' + data.test);
	  }
	});
}

user.js

//用户内容
requestUrl('https://raw.githubusercontent.com/czy88840616/avalon-node/master/package.json', function(data) {
	//修改数据
	data.test = 1;
})