How can I use variables in package.json?

Question

There is a feature from maven I miss a lot in package.json. In maven .pom file you can define variables in parent project and use them in child project\'s pom files.

Answer 1

Define a config object in package.json:

{
    "name"   : "myapp",
    "config" : { "port" : "3000" },
    ...
}

And then you can access port value from scrips object with $npm_package_config_port

{
    "name"   : "myapp",
    "config" : { "port" : "3000" },
    "scripts": {
        "start" : "node --harmony app.js $npm_package_config_port"
    },
    ...
}

The source full article is here:

http://www.marcusoft.net/2015/08/npm-scripting-configs-and-arguments.html#npm-configuration