Adding a field in trip objects to cover cancelled trips easier

[pierre-bouffort]

Adding a field in trip objects to cover cancelled trips easier

[jiffyclub]

It is possible, though somewhat cumbersome, to determine if a trip was cancelled by cross-referencing with status changes. There is a trip_cancel event type and the events schema contains any related trip IDs.

[kevin-courbet-blue]

There might be race conditions where the trip is sent before the event (the standard does not enforce the sequence of events). I don't think we want to reject a trip event simply because it arrived earlier than the status change event.
Further, some providers may only implement a Trips endpoint feed for instance, and then there would be no status change event to reference.
Lastly, this request for change is also to improve data integrity by offering a means to validate different shapes of trips, such as "no show" trips which are a common use case, for which some fields may be unavailable (such as distance). Currently, the standard's definition is either too restrictive at times (duration required but does not exist for a cancelled trip), or too loose ("optionally required" mentions, but sometimes it is not clear when that field should be required or not). This change (along with Issue #888 ) would be a step towards tighter type definitions for events, to improve data quality across the board.