How to test a vue component that has methods that do ajax calls

Using karma and jasmine. How do I properly write a test that runs a method like the following:

methods {
    getAddress: function () {
          Addresses.show()
            .then((response) => {
                if (response.error && response.code === 404) {
                    this.editAddress = true;
                }
                    this.address = response;
            });
      }
}

Addresss.show() is calling an api to get an address. I've read that some people are faking the responses, but I don't know how to do that in this case. Any thoughts?

I tried changing the function getAddress() to take a parameter (Addresses) in which I'd call getAddress(Addresses), with a modified Addresses.show() method. But it still needs to return a promise, because the method getAddresses is using a .then to set the data.