How to get current model or model value in ember unit test cases

I'm trying to get model value in ember unit test cases, but its's throwing error like currentModel is destroyed or not define.

Unit test code:

test('test userInfo', function (assert) {
    let appRoute = this.subject();
    let response = {
        "name ": "Test User"  
    }
    appRoute.getUserInfo(response);
    assert.equal(appRoute.get('currentModel.userInfo'), response.name, "userInfo value");
    assert.ok(appRoute);
});

Application route code:

getUserInfo: function (response) {
    this.set('currentModel.userInfo', response.name);
},