How to Write Global Functions in Postman

Question

I need help writing a common function to use across a collection of requests which will help with building a framework.

I have tried using the below format

Answer 1

I use this little hack:

pm.globals.set('loadUtils', function loadUtils() {
    let utils = {};
    utils.reuseableFunction = function reuseableFunction() {
        let jsonData = JSON.parse(responseBody);
    }
    return utils;
} + '; loadUtils();');
tests['Utils initialized'] = true;

In another request I can reuse the global variable loadUtils:

const utils = eval(globals.loadUtils);
utils.reuseableFunction();

You can also check the developer roadmap of the Postman team. Collection-level scripts are on the near-term agenda and should be available soon until then you can use the shown method.

Answer 2

A more elegant way consists of using the global context (not variables) in the pre-request scripts. For example, if you wish a function called myFunction to be available in any pre-request script, you can go to Edit Collection/Pre-request and set

globalThis.myFunction = function(){}

Then you can call myFunction in any pre-request script of any request inside the collection (without any stringification/evaluation of your function)