behavior for update without any parameters

[frehner]

Hopefully an easier question: if I'm reading the WebIDL definition correctly, you could potentially call appHistory.update() without any parameters, correct? (Also note that the definition for update appears to match push exactly, and it is explicitly stated that push can be called without a parameter)

Promise<undefined> update(USVString url, optional AppHistoryEntryOptions options = {});
Promise<undefined> update(optional AppHistoryEntryFullOptions options = {});
Promise<undefined> update(AppHistoryNavigationCallback);

In this case, what is the expected behavior of appHistory.update() (regarding updates to url and/or state, as well as event listeners)?

[domenic]

Great question. I could swear I disallowed this at one point, but not recently at least...

I think the only sensible option would be for it to do nothing, so probably it's better for it just to throw.

[domenic]

Oh, I remember the issue now. Web IDL enforces a rule that any trailing dictionaries with non-required members be marked optional. This works poorly for cases like this, where we want to require "the dictionary must contain at least one value". That has to be specified in prose, not IDL. See whatwg/webidl#903.

I'll add a comment to the IDL to remind us of this, and it'll become much clearer when it's fully specced.