what's the prototype of a protocol look like?

[michaelficarra]

Since we construct them with new, I assume that implies there's a Protocol.prototype. Does it have anything on it? Is it frozen? What is its prototype? If we don't want them to have a [[Prototype]], should we change Protocol to not be invoked with new?

[ljharb]

I don't think the presence of a [[Prototype]] has an impact on "uses new" - new is for constructors that produce objects, and that applies here.

I don't think it needs anything on it, but I also don't think it needs to be frozen (or should be). It'd be fine to have it as an empty object imo. It would also be fine to have protocols with a [[Prototype]] set to null.

[LeaVerou]

If we truly want protocols to be immutable, we should not have any mutable objects in their prototype chain.
But do we actually want protocols to be immutable objects, or do we just want their essential features (name, parent protocols, required members, provided members) to be immutable? The latter doesn't necessarily require the actual objects to be immutable (though that's one way to achieve it).

[ljharb]

I think that the only part that really matters is the essential features, and going beyond that prevents future polyfilling, and should be considered very carefully.