isSameSite should clearly state that the answer may change over time due to PSL changes

[erik-anderson]

Since the Public Suffix List can change what isSameSite returns, there should at least be a note to developers warning them of that.

Naming it isCurrentlySameSite may be a non-shaming name that also conveys that the answer may change over time.

[mikewest]

Hey Erik! I am more enthusiastic about a note than a name change, but I understand and agree with the concern you're raising. Still, I wonder whether this is a special-enough case to justify explicitly labeling something as potentially temporary? We don't do that for other temporary-yet-potentially-cached things like the user's time zone or language preferences (my brain is fried, so I'm not coming up with more compelling examples, but the platform is full of interesting information on which developers predicate decisions that are also ephemeral in nature).

[erik-anderson]

The sentiment I believe I was hearing from the room was that, for many developers, it's probably not intuitive that this answer can change over time (based on changes to the Public Suffix List). PSL and how it results in different eTLD+1s are, in my experience, not something that is well understood.

The non-staticness of things like time zones and language preferences is (IMO) much more intuitive. But perhaps there's some other existing, less intuitive examples with a similar risk.

That said, it's fair to ask if an API name is really the best way to convey this context. An informational note in the spec and/or MDN may be sufficient.

[mikewest]

I added a note in whatwg/html@2904ac2 that I hope addresses this. I'll close this out, but if you think the text is insufficient (or you change your mind about the naming issue), leave comments on the PR?

Thanks for the feedback!