fix(validator): add missing stop_times validation items

Check that timepoints have times and that a stop time without pickup/drop off is a timepoint
(otherwise it has no purpose)

re #167

src/main/java/com/conveyal/gtfs/error/NewGTFSErrorType.java

@@ -50,7 +50,9 @@ public enum NewGTFSErrorType {
     STOP_LOW_POPULATION_DENSITY(Priority.HIGH, "A stop is located in a geographic area with very low human population density."),
     STOP_NAME_MISSING(Priority.MEDIUM, "A stop does not have a name."),
     STOP_GEOGRAPHIC_OUTLIER(Priority.HIGH, "This stop is located very far from the middle 90% of stops in this feed."),
+    STOP_TIME_UNUSED(Priority.LOW, "This stop time allows neither pickup nor drop off and is not a timepoint, so it serves no purpose and should be removed from trip."),
     STOP_UNUSED(Priority.MEDIUM, "This stop is not referenced by any trips."),
+    TIMEPOINT_MISSING_TIMES(Priority.MEDIUM, "This stop time is marked as a timepoint, but is missing both arrival and departure times."),
     TRIP_EMPTY(Priority.HIGH, "This trip is defined but has no stop times."),
     TRIP_HEADSIGN_CONTAINS_ROUTE_NAME(Priority.LOW, "A trip headsign contains the route name, but should only contain information to distinguish it from other trips for the route."),
     TRIP_HEADSIGN_SHOULD_DESCRIBE_DESTINATION_OR_WAYPOINTS(Priority.LOW, "A trip headsign begins with 'to' or 'towards', but should begin with destination or direction and optionally include waypoints with 'via'"),

src/main/java/com/conveyal/gtfs/validator/SpeedTripValidator.java

@@ -1,6 +1,7 @@
 package com.conveyal.gtfs.validator;
 
 import com.conveyal.gtfs.error.NewGTFSError;
+import com.conveyal.gtfs.error.NewGTFSErrorType;
 import com.conveyal.gtfs.error.SQLErrorStorage;
 import com.conveyal.gtfs.loader.Feed;
 import com.conveyal.gtfs.model.Entity;
@@ -47,14 +48,20 @@ public void validateTrip(Trip trip, Route route, List<StopTime> stopTimes, List<
         double distanceMeters = 0;
         for (int i = beginIndex + 1; i < stopTimes.size(); i++) {
             StopTime currStopTime = stopTimes.get(i);
+            if (currStopTime.pickup_type == 1 && currStopTime.drop_off_type == 1 && currStopTime.timepoint == 0) {
+                // stop_time allows neither pickup or drop off and is not a timepoint, so it serves no purpose.
+                registerError(currStopTime, NewGTFSErrorType.STOP_TIME_UNUSED);
+            }
             Stop currStop = stops.get(i);
             // Distance is accumulated in case times are not provided for some StopTimes.
             distanceMeters += fastDistance(currStop.stop_lat, currStop.stop_lon, prevStop.stop_lat, prevStop.stop_lon);
             // Check that shape_dist_traveled is increasing.
             checkShapeDistTraveled(prevStopTime, currStopTime);
             if (missingBothTimes(currStopTime)) {
                 // FixMissingTimes has already been called, so both arrival and departure time are missing.
-                // The spec allows this. Other than accumulating distance, skip this StopTime.
+                // The spec allows this. Other than accumulating distance, skip this StopTime. If this stop_time serves
+                // as a timepoint; however, this is considered an error.
+                if (currStopTime.timepoint == 1) registerError(currStopTime, NewGTFSErrorType.TIMEPOINT_MISSING_TIMES);
                 continue;
             }
             if (currStopTime.departure_time < currStopTime.arrival_time) {