By: Tom Sydney Kerckhove <syd@cs-syd.eu>
ical-recurrence: test that an hourly recurrence rule does not crash recurrenceRuleDateTimeOccurrences ends in a catch-all arm that calls error, so any calendar containing one of the three sub-daily frequencies throws an ErrorCall from pure code. A caller cannot catch that through Conform, which is the whole point of recurring inside it. Hourly, minutely and secondly are legal RFC 5545 frequencies, so this should either recur as asserted here or, until it is implemented, fail as an unfixable RecurrenceError. The catch-all also hides the gap from the exhaustiveness checker, so adding a frequency would not point here. The four pending examples in ICal.Recurrence.RecurrenceRuleSpec already document the missing feature; this one is about the failure mode.