Bash script calls a .js file with a function that should update global variable, but it doesn’t

I have a updateGlobalVar.js file which looks as following:

var globalVar = 111;

async function setGlobalVar() {
    globalVar = 222;
}

setGlobalVar();

Also, I have a bash script, which retrieves that globalVar value, and looks as following:

#!/bin/bash

npm run /updateGlobalVar.js
GLOBAL_VAR=$(grep -Po '(?<=^var globalVar = ).*?(?=;)' ./updateGlobalVar.js)

echo $GLOBAL_VAR

The problem here is the bash script prints out initial 111 instead of an updated 222.

The way I understand that flow is:

  • npm run /updateGlobalVar.js runs updateGlobalVar.js (and I am sure it does);
  • function setGlobalVar() is called (and I am sure it is);
  • globalVar should be now updated and printed with a new 222 value. But it doesn’t.

Moreover, when I modify my file to “debug” using the console.log() within the updateGlobalVar.js file like:

var globalVar = 111;
console.log(globalVar);

async function setGlobalVar() {
    globalVar = 222;
}

setGlobalVar();
console.log(globalVar);

It returns 111 in both console.log(globalVar) cases, which makes me think that globalVar is never updated.

Looks like I miss something fundamental regarding the work with global variables, still am struggling to figure that out.

May this be somehow related to the asynchronous nature of the setGlobalVar() function?