Add a frozen record type?

[littledan]

WebAssembly module instantiation creates an exports object which is frozen. This is not a frozenarray, it's more like a frozen record, since the keys are arbitrary strings. It seems like if I declare the WebIDL type to be a record, I can't just call SetIntegrityLevel(array, "frozen") in my own spec, since I don't have access to the object after it is converted by WebIDL. Would it make sense to define a new type here?

[domenic]

This is a return type, right? In that case I'd just use object personally. Others don't always agree with me, but I find worrying about Web IDL return types a bit silly, since they don't have JS-observable impacts (like how argument types cause coercion algorithms to run).

[bzbarsky]

For now, I agree: use object and manual definition of things on it. If we end up with multiple consumers that want this, we can think about specifying something.

[littledan]

OK, sounds good, thanks!

[annevk]

@domenic one thing that we rely on in places is that returning a byte sequence to something that returns a ByteString in IDL does the right thing. There's also things like that for things that return a sequence (which turns whatever into an Array). Return values definitely have some impact, if only converting from IDL to JavaScript, but as I've shown also more.