paackage.json

Specifying Packages

To specify the packages your project depends on, you need to list the packages you'd like to use in your package.json file. There are 2 types of packages you can list:

• "dependencies": these packages are required by your application in production
• "devDependencies": these packages are only needed for development and testing

Manually editing your package.json

You can manually edit your package.json. You'll need to create an attribute in the package object called dependencies that points to an object. This object will hold attributes named after the packages you'd like to use, that point to a semver expression that specifies what versions of that project are compatible with your project.

If you have dependencies you only need to use during local development, you will follow the same instructions as above but in an attribute called devDependencies.

For example: The project below uses any version of the package my_dep that matches major version 1 in production, and requires any version of the packagemy_test_framework that matches major version 3, but only for development:

{
  "name": "my_package",
  "version": "1.0.0",
  "dependencies": {
    "my_dep": "^1.0.0"
  },
  "devDependencies" : {
    "my_test_framework": "^3.1.0"
  }
}

The --save and --save-dev install flags

The easier (and more awesome) way to add dependencies to your package.json is to do so from the command line, flagging the npm install command with either --saveor --save-dev, depending on how you'd like to use that dependency.

To add an entry to your package.json's dependencies:

npm install <package_name> --save

To add an entry to your package.json's devDependencies:

npm install <package_name> --save-dev