[bug] Every skate element gains property getters/setters of all other skate element.

[trusktr]

Bug report

Delete this section if this is a feature request.

• Skate version: v5.2.4
• Affected browsers (and versions): all

Current behaviour

After defining multiple classes with withUpdate, every instance of all classes will have the combination of all property getters/setters from every class in the application.

Expected behaviour

Each element instance should only have the property getters/setters of the props defined by it's class, not those of any other class.

more details

The reason this happens is because there's an _observedAttributes array on the WithUpdate class. This array is shared with all class constructor instances that inherit from WithUpdate.

The problem is similar to placing an array as a prototype property, and having all instances push/pop to/from it.

The solution is to create one array per constructor that inherits from WithUpdate. We can do that by placing the following line at the top of the static get observedAttributes getter:

    static get observedAttributes(): Array<string> {
      if (!('_observedAttributes' in this)) this._observedAttributes = [] // THIS LINE
      defineProps(this, WithUpdate);
      return this._observedAttributes.concat(super.observedAttributes || []);
    }

It causes a new array to be created per class instance, instead of using the shared array defined by static _observedAttributes = [];.

[trusktr]

Uh oh, I just noticed that this applies with _attributeToAttributeMap and _attributeToPropertyMap too! Each new subclass will clobber other subclass definitions if they have the same attribute names.

It doesn't look like these problems exist in the latest master any more.

[trusktr]

I found the skate-5.2.4 commit and made a branch with the same name so that I could make a PR with the fixes: #1561

[treshugart]

It doesn't look like these problems exist in the latest master any more.

Can you confirm? If so can we close this?