Install node package dynamically according to parameters - node.js

Question

I need to update the node.js package.json dynamically for example
if I run npm start with param A it will install
for example if I run npm start A it will start
{
"name": "simplenodeapp",
"main": "app.js",
"scripts": {
"start": "node app.js" <some param",
},
"license": "ISC",
"dependencies": {
"express":"*"
},
}
And if I run npm start B
{
"name": "simplenodeapp",
"main": "app.js",
"scripts": {
"start": "node app.js" <some param>",
},
"license": "ISC",
"dependencies": {
"HAproxy":"*"
},
}
is it possible ? I need to do it programmatically...

Answer 1

UPDATE:
I hope I finally understand the question being asked.
NPM allows you to define config objects and pass in dynamic arguments. These can be used separately or combined quite powerfully.
In the comments below, the OP asked how to run node with two different file names. This can be accomplished in two different ways.
Option 1:
{
"name": "test",
"version": "1.0.0",
"main": "index.js",
"author": "Skyler Hair",
"license": "MIT",
"config": {
"A": "index.js",
"B": "app.js"
},
"scripts": {
"start:A": "node $npm_package_config_A",
"start:B": "node $npm_package_config_B"
}
}
npm run start:A OR npm run start:B
Option 2:
{
"name": "test",
"version": "1.0.0",
"main": "index.js",
"author": "Skyler Hair",
"license": "MIT",
"scripts": {
"start": "node"
}
}
npm run start -- index.js OR npm run start -- app.js
ORIGINAL ANSWER:
You can create a script that runs npm install and accepts the dependencies as arguments. For example,
{
"name": "test",
"version": "1.0.0",
"main": "index.js",
"license": "MIT",
"author": "Skyler Hair",
"scripts": {
"install": "npm install"
}
}
can be run using
npm run install -- express <other dependency> <another dep>