Nodemon – Automatic Restart the node application

What is Nodemon ?

Nodemon is a tool that helps develop node.js based applications by automatically restarting the node application when file changes in the directory are detected.

nodemon does not require any additional changes to your code or method of development. nodemon is a replacement wrapper for node, to use nodemon replace the word node on the command line when executing your script.

Features

• Automatic restarting of application.
• Detects default file extension to monitor.
• Default support for node & coffeescript, but easy to run any executable (such as python, make, etc).
• Ignoring specific files or directories.
• Watch specific directories.
• Works with server applications or one time run utilities and REPLs.
• Requirable in node apps.
• Open source and available on github.

Nodemon Installation

Either through cloning with git or by using npm (the recommended way):

npm install -g nodemon

Now will be installed globally to your system path.

You can also install as a development dependency:

npm install --save-dev nodemon

With a local installation, nodemontool will not be available in your system path. Instead, the local installation of nodemon can be run by calling it from within an npm script (such as npm start) or using npx nodemon.

Usage

nodemontool wraps your application, so you can pass all the arguments you would normally pass to your app:

nodemon [your node app]

For CLI options, use the -h (or --help) argument:

nodemon -h

Using this tool is simple, if my application accepted a host and port as the arguments, I would start it as so:

nodemon ./server.js localhost 8080

Any output from this script is prefixed with [nodemon], otherwise all output from your application, errors included, will be echoed out as expected.

If no script is given, nodemon will test for a package.json file and if found, will run the file associated with the main property (ref).

You can also pass the inspect flag to node through the command line as you would normally:

nodemon --inspect ./server.js 80

If you have a package.json file for your app, you can omit the main script entirely and it will read the package.json for the main property and use that value as the app.

nodemon will also search for the scripts.start property in package.json (as of nodemon 1.1.x).