I am testing a function which calls another function that return promise, I have tried with async/await, done and resolves and rejects but nothing work. code -

let total = 0;

function sum(a, b) {
    return new Promise((res, rej) => {
        setTimeout(() => {
            res(a + b);
        }, 0)
    });
}

function wrapper() {
    sum(2,3)
        .then(data => {
            total = data;
        })
        .catch(err => {
            console.log(err);
        })
}

describe('Test', () => {
    it('adds 2 + 3 to equal 5', () => {
        // want to call wrapper and test that total is equal to 5 
    });
})

I want to call the wrapper function and wait till, then or catch block executes and it stores the data to total, but jest is not waiting for it.