IronmanJS

Bringing Ironman mode to JavaScript - JavaScript without bloat.

Do you think that JavaScript has too many packages? Are you looking for a challenge? Do you want to ensure you have absolutely no dependencies? Do you want bragging rights? Or are you just old school? If you answered yes to any of these questions then IronmanJS is for you.

This simple (yet effective) package prevents any other packages from being installed in your codebase. It does so by scanning package.json for any (and all) dependencies, if it detects any additional dependencies it throws an error.

Usage

Using IronmanJS is simple and easy, simply include this single line at the beginning of any one file that is used in your app (I recommend your app's entrypoint):

require('ironmanjs');

It is usually desirable to only run code after package.json is checked (although this will not affect whether ironmanjs throws an error or not). In this case a callback can be supplied to the default export like so:

function main() {
    console.log('This code is better than before');
}

require('ironmanjs')(main);

Caveats

The callback is necessary because reading a file takes longer to execute than simple JavaScript, for example the following code will result in "Hello World!" being printed before the ironmanjs error is thrown.

require('ironmanjs');
console.log('Hello World!');

For this reason it is not recommended to call the default export after the require statement, because then it becomes much harder to predict the order of execution and therefore if the callback will be called, for example in cases like this:

const setcb = require('ironmanjs');

(() => {
    // Some long running code
})();

// Callback may never be called if ironmanjs' check completes before IIFE
setcb(() => {
    console.log('Hello World!');
});

TypeScript and whitelists

I am working on a TypeScript based version of the code, however, to support this use case (and others) we allow for a whitelist to be created in your .env file. Since reading values from .env requires the dotenv package this package must be added to the whitelist.

// .env
IRONMANJS_WHITELIST='typescript,axios,dotenv'

For this code to then behave correctly the dotenv package must be run before ironmanjs is required:

// Any imports can appear above (or below) the entrypoint
import { post } from 'axios'

// This should be the entrypoint of your app
require('dotenv').config();
require('ironmanjs')(() => {
    // Your code here
});

I recommend using the require function over import statements for both the dotenv package and the ironmanjs package, this is because it is more predictable than the corresponding import statements. However, this is only in the case of ironmanjs and dotenv you are then free to use whatever syntax for the rest of your imports.

Of course it goes without saying, if you use this feature you are no longer using ironman JavaScript, and you immediately lose all bragging rights.