npmcs

npmcs is a tool for easily defining scripts that run depending on the host operating systems platform, enabling you to run scripts without worrying about ensuring a script will run on both windows and linux. Furthermore, because scripts are defined in a .js file rather than .json, scripts can be commented making it easier to work with.

npmcs also allows you to quickly set environmental variables and have them change across different operating systems. If you're running windows npmcs will use set ENV_VAR=value for command prompt or $env:ENV_VAR=value if using powershell. If you are on a unix based os export ENV_VAR=value will be used to set environmental variables.

Installation

Installation as a dev dependency (recommended):

npm install --save-dev npmcs

alternatively npmcs can be installed globablly:

npm install -g npmcs

With npmcs, you define an npmcs-scripts.js file in the root directory of your application:

//npmcs-scripts.js
module.exports = {
	scripts: {
		/*
            Windows scripts, run on a windows environment
        */
		win: {
			start: 'start npm run dev',
			dev: 'SET NODE_ENV=development && npm run build && npm run nodemon',
			prod: 'SET NODE_ENV=production node src/app.js',
			nodemon: 'nodemon --debug src/app.js',
			build: 'start webpack -d --watch',
			test: 'echo "Error: no test specified" && exit 1'
		},
		/*
            Unix scripts, run on a unix environment
        */
		nix: {
			start: 'npm run dev',
			dev: 'export NODE_ENV=development && npm run build && npm run nodemon',
			prod: 'export NODE_ENV=production node src/app.js',
			nodemon: 'nodemon --debug src/app.js',
			build: 'webpack -d --watch',
			test: 'echo "Error: no test specified" && exit 1'
		},
		/* 
			Additionally add different commands for osx: (note that if running npmcs
			on osx and this is not specified it will then look to nix for the commands
			to run.
		*/
		osx:{

		}
	}
}

Calling npmcs will then invoke the right command depnding on the current operating system.

A package.json using npmcs may end up looking like the following if installed via --save-dev

"scripts": {
   //Tell npmcs to run the "start" script specified in npmcs-scripts.js
   "start": "node node_modules/npmcs/bin start"
}

With npmcs it is also possible to define scripts that are shared across operating systems, thus the example shown earlier would become:

//npmcs-scripts.js
module.exports = {
	scripts: {
		//nodemon, build and test commands same regardless of running on windows/linux (remove duplication)
		nodemon: 'nodemon --debug src/app.js',
		build: 'start webpack -d --watch',
		test: 'echo "Error: no test specified" && exit 1'
		/*
            Windows scripts, run on a windows environment
        */
		win: {
			start: 'start npm run dev',
			dev: 'SET NODE_ENV=development && npm run build && npm run nodemon',
			prod: 'SET NODE_ENV=production node src/app.js',
		},
		/*
            Unix scripts, run on a unix environment
        */
		nix: {
			start: 'npm run dev',
			dev: 'export NODE_ENV=development && npm run build && npm run nodemon',
			prod: 'export NODE_ENV=production node src/app.js',
		},
	}
}

Installation quickstart

Create a new file name npmcs-scripts.js in the root of your directory and paste the following:

module.exports = {
	scripts: {
		win: {
			start: 'node src/app.js',
		},
		nix: {
			start: 'node src/app.js',
		}
	},
	env: {
		win: {
			NODE_ENV: 'development'
		},
		nix: {
			NODE_ENV: 'development'
		}
	}
};

Your package.json file should then look like the following:

"scripts": {
    "start": "node node_modules/npmcs/bin start"
}

Environment

npmcs also allows you to define environmental variables in a cross platform way by specifying "env" within the scripts portion of your package.json file.

This will not override any environmental settings that may have been set in your commands making it perfectly safe to split setting environmental variables between the script commands and the env setting.

The following script sets the NODE_ENV environment variable no matter if you're running on windows or linux/unix.

module.exports = {
   env: {
        NODE_ENV: "development"
   }
}

This can be further refined by setting environmental variables based on the running platform:

module.exports = {
    env: {
		win: {
			NODE_ENV: 'development'
		},
		nix: {
			NODE_ENV: 'development'
		}
	}
}

npmcs will look for environmental variables for a specific platform first before defaulting to the outer env object to find environmental variables. Thus anything defined in env will be set on all os environments, unless it is overriden by something more specific. An example is shown below:

module.exports = {
   env: {
   	NODE_ENV: 'development'
   	win: {
   	    NODE_ENV: 'production'
   	},
   	nix: {
   	    NIX_ENV: 'ImOnNix'
   	}
   }
}

In the example above, npmcs will set NODE_ENV to production on windows, but on nix will set it to development as nix does not override the NODE_ENV setting.

npcms also lets you define environmental variables based on if you're running in development or production mode. To achieve this, you append -production or -development to the entries within the env.

module.exports =  {
    env: {
        'win-production':{
            NODE_ENV: "production"
        },
        'win-development':{
            NODE_ENV: "development"
        },
        'nix-production':{
            NODE_ENV: "development",
            ONLY_ON_NIX:"SomethingNixSpecific"
        },
        'nix-development':{
            NODE_ENV: "development",
            ONLY_ON_NIX:"SomethingNixSpecific"
        }
    }
}

For development/production to work you must provide npcms an argument specifying if youre running development or production, thus the command becomes:

node node_modules/npmcs/bin [start] development

or similarily:

node node_modules/npmcs/bin [start] production

and a corresponding package.json may look like this:

"scripts": {
   //Tell npmcs to run the "start" script for the current platform and set environmental variables from 
   //[platform]-development
   "start": "node node_modules/npmcs/bin start development"
}

Change log

[x] v1.4.1 Supports powershell, now cycles through scripts recursively so npm run can be used anywhere. Updated readme.

[x] v1.4.2 Now detects and searches for osx key and then defaults to nix setting if osx is not found for backwards compatability. Also now encloses environmental values that are multiple words in quotes.