Is it possible to automatically install the required modules for a node.js script?

Question

Is it possible to automatically download the required modules for a node.js script? I\'m wondering if it\'s possible to generate a list of required modules for a node.js scr

Answer 1

I was inspired by @Aminadav Glickshtein's answer to create a script of my own that would synchronously install the needed modules, because his answer lacks these capabilities.

I needed some help, so I started an SO question here. You can read about how this script works there.
The result is as follows:

const cp = require('child_process')

const req = async module => {
  try {
    require.resolve(module)
  } catch (e) {
    console.log(`Could not resolve "${module}"\nInstalling`)
    cp.execSync(`npm install ${module}`)
    await setImmediate(() => {})
    console.log(`"${module}" has been installed`)
  }
  console.log(`Requiring "${module}"`)
  try {
    return require(module)
  } catch (e) {
    console.log(`Could not include "${module}". Restart the script`)
    process.exit(1)
  }
}

const main = async () => {
  const http    = await req('http')
  const path    = await req('path')
  const fs      = await req('fs')
  const express = await req('express')

  // The rest of the app's code goes here
}

main()

And a one-liner (139 characters!). It doesn't globally define child_modules, has no last try-catch and doesn't log anything in the console:

const req=async m=>{let r=require;try{r.resolve(m)}catch(e){r('child_process').execSync('npm i '+m);await setImmediate(()=>{})}return r(m)}

const main = async () => {
  const http    = await req('http')
  const path    = await req('path')
  const fs      = await req('fs')
  const express = await req('express')

  // The rest of the app's code goes here
}

main()