Why does the promise resolve?

user_4805148 0
Viewed 53

I have the following code:

class Request {
  constructor(method, url) {
    this.method = method;
    this.url = url;
  }

  send() {
    return fetch(this.url, { method: this.method })
      .then((res) => res.json());
  }
}

const url = "https://ron-swanson-quotes.herokuapp.com/v2/quotes";
const getQuotes = new Request("get", url);

const all = {
  getQuotes
};

getQuotes.send().then(alert);
delete all.getQuotes;

Can somebody, please, explain why does getQuotes.send() resolve even after I have explicitly deleted a class instance on which the promise was executed.

promise asynchronous javascript
2 Answers

You have deleted the reference to the Request instance from the all object. I.e. removed the getQuotes property. The getQuotes const defined previously is still there and the promise is still running.

user_12570940

Because you run promise by .then((res) => res.json()); (inside send(), and also further by .then(alert)). By the way: when you execute code

const getQuotes = new Request("get", url);
const all = { getQuotes };

then you request object is in two places: in getQuotes constant, and in all.getQuotes object field. So when you executed delete all.getQuotes, the getQuotes constant is still not empty (but this is not reason of promise execution).

user_8600990
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