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

The following function is declared in the Test tab in the first function

postman.setGlobalVariable("function", function function1(parameters)
{
  //sample code
});

I used the following in the pre-request

var delay = eval(globals.function);
delay.function1(value1);

I am getting the following error

there was error while evaluating the Pre-request script : Cannot read property 'function1' of undefined.

Can anyone help me with how to define Global/common functions and use them across the requests?

Thanks in advance

Answer 1

Without eval:

Define an object containing your function(s) in the collection's pre-request scripts without using let, var, etc. This attaches it to Postman's global sandbox object.

utils = {
  myFunc: function() {
    return 'hello';
  }
};

Then within your request's pre-request or test script section just call the function:

console.log(utils.myFunc());

Answer 2

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.