How do I add a custom script to my package.json file that runs a javascript file?

Steps are below:

1. In package.json add:

   "bin":{
       "script1": "bin/script1.js" 
   }
   

2. Create a bin folder in the project directory and add file runScript1.js with the code:

   #! /usr/bin/env node
   var shell = require("shelljs");
   shell.exec("node step1script.js");
   

3. Run npm install shelljs in terminal

4. Run npm link in terminal

5. From terminal you can now run script1 which will run node script1.js

Reference: http://blog.npmjs.org/post/118810260230/building-a-simple-command-line-tool-with-npm

I have created the following, and it's working on my system. Please try this:

package.json:

{
  "name": "test app",
  "version": "1.0.0",
  "scripts": {
    "start": "node script1.js"   
  }
}

script1.js:

console.log('testing')

From your command line run the following command:

npm start

Additional use case

My package.json file has generally the following scripts, which enable me to watch my files for typescript, sass compilations and running a server as well.

 "scripts": {
    "start": "concurrently \"sass --watch ./style/sass:./style/css\" \"npm run tsc:w\" \"npm run lite\" ",    
    "tsc": "tsc",
    "tsc:w": "tsc -w", 
    "lite": "lite-server",
    "typings": "typings",
    "postinstall": "typings install" 
  }

Custom Scripts

npm run-script <custom_script_name>

or

npm run <custom_script_name>

In your example, you would want to run npm run-script script1 or npm run script1.

See https://docs.npmjs.com/cli/run-script

Lifecycle Scripts

Node also allows you to run custom scripts for certain lifecycle events, like after npm install is run. These can be found here.

For example:

"scripts": {
    "postinstall": "electron-rebuild",
},

This would run electron-rebuild after a npm install command.