VehicleJourneyAtStop: Handle nil value when checking offset within range

Old `VehicleJourneyAtStop`s were created before I added a database
default of 0 to those records. Thus old data will not have the proper 0
value to check against, and our `<` `>` comparisons trigger an error due
to a comparison with `nil`.

To get around the error, set a default value of 0 (the current day) when
the offset isn't set.

I think that ideally this should be solved at the database level with a
data migration, but hopefully this is okay for now. Whenever we do
decide to do a data migration, however, this code needs to be deleted.

Refs #3597

2 files changed, 14 insertions, 0 deletions

diff --git a/app/models/chouette/vehicle_journey_at_stop.rb b/app/models/chouette/vehicle_journey_at_stop.rb
index 3c350b2ae..35d94aa75 100644
--- a/app/models/chouette/vehicle_journey_at_stop.rb
+++ b/app/models/chouette/vehicle_journey_at_stop.rb
@@ -59,6 +59,10 @@ module Chouette
     end
 
     def day_offset_outside_range?(offset)
+      # At-stops that were created before the database-default of 0 will have
+      # nil offsets. Handle these gracefully by forcing them to a 0 offset.
+      offset ||= 0
+
       offset < 0 || offset > DAY_OFFSET_MAX
     end
 
diff --git a/spec/models/chouette/vehicle_journey_at_stop_spec.rb b/spec/models/chouette/vehicle_journey_at_stop_spec.rb
index 58616b066..38196bb88 100644
--- a/spec/models/chouette/vehicle_journey_at_stop_spec.rb
+++ b/spec/models/chouette/vehicle_journey_at_stop_spec.rb
@@ -19,6 +19,16 @@ RSpec.describe Chouette::VehicleJourneyAtStop, type: :model do
         Chouette::VehicleJourneyAtStop::DAY_OFFSET_MAX
       )).to be false
     end
+
+    it "forces a nil offset to 0" do
+      at_stop = build_stubbed(
+        :vehicle_journey_at_stop,
+        arrival_day_offset: nil,
+        departure_day_offset: nil
+      )
+
+      expect(at_stop.day_offset_outside_range?(nil)).to be false
+    end
   end
 
   describe "#validate" do