core-js-pure/features/set with custom objects

[jml6m]

Seeing some errors. I have class Foo as such:

export class Foo {
  name;

  constructor(name) {
    this.name = name;
  }
}

I'd like to use the Set.isSubsetOf() method but neither core-js-pure/features/set or core-js/features/set gives me fully what I want:

import Set from "core-js-pure/features/set";
import { Foo } from "./Foo.js";

let q1, q2, q3, test, test2;
q1 = new Foo("q1");
q2 = new Foo("q2");
q3 = new Foo("q3");

test= new Set([q1, q2]);
test2= new Set([q1, q2, q3]);

console.log(test); // prints Set {}
console.log(test2); // prints Set {}
console.log(Set.isSubsetOf(test,test2)); // prints true

The method works, but my Sets aren't being populated. If I use core-js/features/set on the same code, here is what the console prints:

console.log(test); // prints Set { Foo { name: 'q1' }, Foo { name: 'q2' } }
console.log(test2); // prints Set { Foo { name: 'q1' }, Foo { name: 'q2' }, Foo { name: 'q3' } }
console.log(Set.isSubsetOf(test,test2)); // throws TypeError: _set.default.isSubsetOf is not a function

I'm pretty sure core-js-pure/features/set is the correct import but something is going on with the constructor.

[zloirock]

isSubsetOf is a Set prototype method. You should use

test.isSubsetOf(test2)

[jml6m]

@zloirock Thank you for clarifying here, that did work. However, the other issue I pointed out, you didn't address. Why aren't Sets with custom objects being populated when using core-js-pure/features/set?

[zloirock]

@jml6m I can't understand what do you mean.

[jml6m]

In my post, you'll see the code I create a new Set([q1, q2]); but console.log prints an empty object. The Set is not being created properly.

[zloirock]

If you don't see it in your console, it does not mean that it's not created. It's just problems of your console. Try, for example, new Set([q1, q2]).has(q1) or [...new Set([q1, q2])].