无法使用静态方法返回的类实例访问类方法

Question

I have created a subscriber class to store subscriber details and use a static method to return the instance of the class, but I am not able to set the values using the instance

Here is the subscriber class:

let _instance;

export class Subscriber {

    constructor(username, password) {
        this._username = username;
        this._password = password;
    }


    setSubscriberId(subscriberId) {
        cy.log(subscriberId);
        this._subscriberId = subscriberId;
    }

    setSessionId(sessionId) {
        this.sessionId = sessionId;
    }


    getUserName = () => {
        return this._username;
    }
    getPassword = () => {
        return this._password;
    }

    getSubsciberId() {
        return this._subscriberId;
    }

    getSessionId() {
        return this.sessionId;
    }


    static createSubscriber(username, password) {
        if (!_instance) {
            _instance = new Subscriber(username, password);
        }
        return _intance;
    }

    static getSubscriber() {
        return _instance;
    }
}

I am creating a instance of the class in before block and accessing the instance in Given block

before("Create a new subscriber before the tests and set local storage", () => {
    const username = `TestAutomation${Math.floor(Math.random() * 1000)}@sharklasers.com`;
    const password = "test1234";
    subscriberHelpers.createSubscriber(username, password, true).then((response) => {
        cy.log(response);
        Subscriber.createSubscriber(username, password);
        Subscriber.getSubscriber().setSubscriberId(response.Subscriber.Id);
        Subscriber.getSubscriber().setSessionId(response.SessionId);
    }).catch((error) => {
        cy.log(error);
    });
});

Given(/^I launch selfcare app$/, () => {
    cy.launchApp();
});

Given(/^I Set the environemnt for the test$/, () => {
    cy.log(Subscriber.getSubscriber());
    cy.log(Subscriber.getSubscriber().getSubsciberId());
});

here is the output on the cypress console

Questions:

1. Why the subscriberID is null even though I am setting it in the before block
2. if I print the subscriber Object why am I not seeing subscriberID

Here is the output of subscriber object

Answer 1

Properties username and password are defined synchronously in before() , so are present on the object when tested.

But subscriberId is obtained asynchronously, so you will need to wait for completion inside the test, eg

cy.wrap(Subscriber.getSubscriber()).should(function(subscriber){
  expect(subscriber.getSubsciberId()).not.to.be.null
})

Refer to wrap - Objects to see how to handle an object with Cypress commands.

and see should - Differences

When using a callback function with .should() or .and(), on the other hand, there is special logic to rerun the callback function until no assertions throw within it.

In other words, should will retry (up to 5 seconds) until the expect inside the callback does not fail (ie in your case the async call has completed).