How to auto-reload files in Node.js?

Question

Any ideas on how I could implement an auto-reload of files in Node.js? I'm tired of restarting the server every time I change a file. Apparently Node.js' require() function does not reload files if they already have been required, so I need to do something like this:

var sys     = require('sys'),      http    = require('http'),     posix   = require('posix'),     json    = require('./json');  var script_name = '/some/path/to/app.js'; this.app = require('./app').app;  process.watchFile(script_name, function(curr, prev){     posix.cat(script_name).addCallback(function(content){         process.compile( content, script_name );     }); });  http.createServer(this.app).listen( 8080 ); 

And in the app.js file I have:

var file = require('./file'); this.app = function(req, res) {      file.serveFile( req, res, 'file.js');   } 

But this also isn't working - I get an error in the process.compile() statement saying that 'require' is not defined. process.compile is evaling the app.js, but has no clue about the node.js globals.

Answer 1

A good, up to date alternative to supervisor is nodemon:

Monitor for any changes in your node.js application and automatically restart the server - perfect for development

To use nodemon with version of Node without npx (v8.1 and below, not advised):

$ npm install nodemon -g $ nodemon app.js 

Or to use nodemon with versions of Node with npx bundled in (v8.2+):

$ npm install nodemon $ npx nodemon app.js 

Or as devDependency in with an npm script in package.json:

"scripts": {   "start": "nodemon app.js" }, "devDependencies": {   "nodemon": "..." } 

Answer 2

node-supervisor is awesome

usage to restart on save for old Node versions (not advised):

npm install supervisor -g supervisor app.js 

usage to restart on save for Node versions that come with npx:

npm install supervisor npx supervisor app.js 

or directly call supervisor in an npm script:

"scripts": {   "start": "supervisor app.js" }