How can I run multiple npm scripts in parallel?

Question

In my package.json I have these two scripts:

  \"scripts\": {
    \"start-watch\": \"nodemon run-babel index.js\",
    \"wp-server\": \"webpack-         


        

Answer 1

How about forking

Another option to run multiple Node scripts is with a single Node script, which can fork many others. Forking is supported natively in Node, so it adds no dependencies and is cross-platform.

---

Minimal example

This would just run the scripts as-is and assume they're located in the parent script's directory.

// fork-minimal.js - run with: node fork-minimal.js

const childProcess = require('child_process');

let scripts = ['some-script.js', 'some-other-script.js'];
scripts.forEach(script => childProcess.fork(script));

---

Verbose example

This would run the scripts with arguments and configured by the many available options.

// fork-verbose.js - run with: node fork-verbose.js

const childProcess = require('child_process');

let scripts = [
    {
        path: 'some-script.js',
        args: ['-some_arg', '/some_other_arg'],
        options: {cwd: './', env: {NODE_ENV: 'development'}}
    },    
    {
        path: 'some-other-script.js',
        args: ['-another_arg', '/yet_other_arg'],
        options: {cwd: '/some/where/else', env: {NODE_ENV: 'development'}}
    }
];

let runningScripts= [];

scripts.forEach(script => {
    let runningScript = childProcess.fork(script.path, script.args, script.options);

   // Optionally attach event listeners to the script
   runningScript.on('close', () => console.log('Time to die...'))

    runningScripts.push(runningScript); // Keep a reference to the script for later use
});

---

Communicating with forked scripts

Forking also has the added benefit that the parent script can receive events from the forked child processes as well as send back. A common example is for the parent script to kill its forked children.

 runningScripts.forEach(runningScript => runningScript.kill());

For more available events and methods see the ChildProcess documentation