Jasmine with helpers

I'm new on Jasmine testing, i need to test a nodejs express application. I do not found any documentation about jasmine helpers else that are called before all tests.

Just tryning i found that adding

beforeAll(async()=>{
   ...
});
afterAll(async()=>{
   ...
});

into my /spec/helpers/myhelper.js these function are executed after and before all code, but i did not found documentation about this behavior into a helper. Is it a standard behavior?

Is it possible to create my helper function into myhelper.js and call this function durng test? how?

my actual /spec/helpers/myhelper.js is :

let server = require("../../app");
console.log('server started before tests....');

function testMethod(){
    console.log("test helper called");
}

How to call my test helper method from my tests?

i'm using jasmine version 3.2.1

from Jasmine with helpers