Throw when passed a 0 for lifetimeDays

[apasel422]

From https://w3c.github.io/ppa/#dom-privateattributionimpressionoptions-lifetimedays:

lifetimeDays, of type unsigned long, defaulting to 30
A "time to live" (in days) after which the impression can no longer receive attribution. If not specified, the default is 30 days. The user agent should impose an upper limit on the lifetime, and silently reduce the value specified here if it exceeds that limit.

[csharrison]

My vote is no.

[martinthomson]

Would you recommend that we require that browsers abort (i.e., throw) if a value of zero is provided? The alternative is to treat the saveImpression call as a noop.

[csharrison]

I prefer throwing. I see no benefit to silently treating it as a no-op.

[apasel422]

+1 for throwing.

[martinthomson]

OK, now we have an issue that is not a question, but a TODO item :) Pull requests welcome.

[bmcase]

Why are we focused on what happens for passing 0? I thought the question was about whether we should allow impressions to be queried a long time after they are placed or should silently reduce time to live value. To which I understood @csharrison vote of "no" to be saying we shouldn't have an upper limit on the lifetime.

[csharrison]

@bmcase sorry there is a misunderstanding, as Martin changed the issue title. The original title of the issue was "Is 0 a valid value for lifetimeDays?"

[bmcase]

Thanks for clarifying @csharrison! I miss understood. In which case you were just responding with "no" zero shouldn't be a valid value. Makes sense now.