Use functions fron another file, without require

Question

Context:

I have 3 files, parent.js, child1.js, and child2.js

parent.js

let child1 = require("./child1.js")
let child2 = require("./child2.js")
let key = "*****"

child1.start(key)
child2.start();

child1.js

let key = false;

module.exports = {
    action: async() => {
        return someApi.get(key);
    },
    start: async(_key) => {
        key = key;
    }
}

child2.js

module.exports = {
    action: async() => {
        let res = await child1.action()
        ...
    },
    start: async() => {
        // startup actions
    }
}

The Problem

I need to run a function from child1 inside child2, but I can't use require because there can only be 1 instance of child1

Does anyone know the solution for this? Thanks

Answer 1

I think that you are asking the wrong question :)
If you need child1 to be unique you should use a singletone and require it wherever you need it.

//child1
let instance

module.export = () => {
  if(!instance) {
     instance = {
    action: async() => {
        return someApi.get(key);
    },
    start: async(_key) => {
        key = key;
    }
   }
   return instance
}

I personally don't love singletone approach but it can be handy

Another approach you can try is to inject child1 service instance into child2 'constructor'
you just have to export a function instead of an object
parent.js

let child1 = require("./child1.js")()
let child2 = require("./child2.js")(child1)
let key = "*****"

child1.start(key)
child2.start();

child2

module.exports = (child1) => {
    
    const action =  async() => {
        let res = await child1.action()
        ...
    }
    const start =  async() => {
        // startup actions
    }
    return {action, start}
}