Node can't find certain modules after synchronous install

Question

I\'ve got a script that synchronously installs non-built-in modules at startup that looks like this

const cp = require(\'child_process\')

function requireOr         


        

Answer 1

cp.execSync is an async call so try check if the module is installed in it's call back function. I have tried it, installation is clean now:

const cp = require('child_process')

function requireOrInstall (module) {
    try {
        require.resolve(module)
    } catch (e) {
        console.log(`Could not resolve "${module}"\nInstalling`)
        cp.execSync(`npm install ${module}`, () => {
            console.log(`"${module}" has been installed`)
            try {
                return require(module)
            } catch (e) {
                console.log(require.cache)
                console.log(e)
            }
        })

    }
    console.log(`Requiring "${module}"`)

}

const http    = require('http')
const path    = require('path')
const fs      = require('fs')
const ffp     = requireOrInstall('find-free-port')
const express = requireOrInstall('express')
const socket  = requireOrInstall('socket.io')

When node_modules not available yet :

When node_modules available already: