Node.js modules are a type of package that can be published to npm.

Overview

  1. Create a package.json file
  2. Create the file that will be loaded when your module is required by another application
  3. Test your module

Create a package.json file

  1. To create a package.json file, on the command line, in the root directory of your Node.js module, run npm init:
  2. Provide responses for the required fields (name and version), as well as the main field:

For more information on package.json files, see "Creating a package.json file".

Create the file that will be loaded when your module is required by another application

Create a file with the same name you provided in the main field. In that file, add a function as a property of the exports object. This will make the function available to other code:

exports.printMsg = function() {
console.log("This is a message from the demo package");
}

Test your module

  1. Publish your package to npm:

  2. On the command line, create a new test directory outside of your project directory.

    mkdir test-directory
  3. Switch to the new directory:

    cd /path/to/test-directory
  4. In the test directory, install your module:

    npm install <your-module-name>
  5. In the test directory, create a test.js file which requires your module and calls your module as a method.

  6. On the command line, run node test.js. The message sent to the console.log should appear.

Resources