Fix stop merging across incompatible location types

Author: JRroony

onebusaway-gtfs-merge/src/main/java/org/onebusaway/gtfs_merge/strategies/StopMergeStrategy.java

@@ -28,6 +28,17 @@ public StopMergeStrategy() {
     _duplicateScoringStrategy.addStrategy(new StopDistanceDuplicateScoringStrategy());
   }
 
+  /**
+   * A stop_time may only reference a stop with location_type=0, never a station or other location
+   * type. If two feeds share a stop_id but disagree on location_type, they are not the same GTFS
+   * entity and must not be merged into one.
+   */
+  @Override
+  protected boolean rejectDuplicateOverDifferences(
+      GtfsMergeContext context, Stop sourceEntity, Stop targetDuplicate) {
+    return sourceEntity.getLocationType() != targetDuplicate.getLocationType();
+  }
+
   @Override
   protected void replaceDuplicateEntry(GtfsMergeContext context, Stop oldStop, Stop newStop) {
     GtfsRelationalDao source = context.getSource();

onebusaway-gtfs-merge/src/test/java/org/onebusaway/gtfs_merge/GtfsMergerTest.java

@@ -471,6 +471,163 @@ public void testStopTimeProxies() throws IOException {
     }
   }
 
+  /**
+   * Reproduction for issue #409: merging two feeds that share a stop_id but disagree on
+   * location_type (one is location_type=0 "stop", the other location_type=1 "station") should never
+   * leave a StopTime referencing the location_type=1 entity, since GTFS trips may only visit
+   * individual stops, not stations.
+   *
+   * <p>Input order: station feed listed first (_oldGtfs), platform feed listed second (_newGtfs).
+   * GtfsMerger processes the LAST listed feed first (see GtfsMerger#run), so the platform feed's
+   * stop (location_type=0) is registered as the target stop first. When the station feed's stop
+   * (location_type=1) is processed, StopMergeStrategy#rejectDuplicateOverDifferences rejects it as
+   * a duplicate due to the location_type mismatch, so it is kept as a separate, renamed Stop
+   * instead of being merged.
+   */
+  @Test
+  public void testLocationTypeMismatch_StationFeedFirstPlatformFeedSecond() throws IOException {
+    _oldGtfs.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Metro,http://metro.gov/,America/Los_Angeles");
+    _oldGtfs.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        "100,Stop 100,47.654403,-122.305211,1");
+    _oldGtfs.putLines("routes.txt", "route_id,route_short_name,route_long_name,route_type", "");
+    _oldGtfs.putLines(
+        "calendar.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "");
+    _oldGtfs.putLines("trips.txt", "route_id,service_id,trip_id", "");
+    _oldGtfs.putLines(
+        "stop_times.txt", "trip_id,stop_id,stop_sequence,arrival_time,departure_time", "");
+
+    _newGtfs.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Metro,http://metro.gov/,America/Los_Angeles");
+    _newGtfs.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        "100,Stop 100,47.654403,-122.305211,0");
+    _newGtfs.putLines(
+        "routes.txt", "route_id,route_short_name,route_long_name,route_type", "R1,1,Route One,3");
+    _newGtfs.putLines(
+        "calendar.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "sid0,1,1,1,1,1,0,0,20120101,20121231");
+    _newGtfs.putLines("trips.txt", "route_id,service_id,trip_id", "R1,sid0,T1");
+    _newGtfs.putLines(
+        "stop_times.txt",
+        "trip_id,stop_id,stop_sequence,arrival_time,departure_time",
+        "T1,100,0,08:00:00,08:00:00");
+
+    StopMergeStrategy stopStrategy = new StopMergeStrategy();
+    stopStrategy.setDuplicateDetectionStrategy(EDuplicateDetectionStrategy.IDENTITY);
+    _merger.setStopStrategy(stopStrategy);
+
+    GtfsRelationalDao dao = merge();
+
+    assertEquals(
+        2,
+        dao.getAllStops().size(),
+        "stops with incompatible location_type must not collapse into one Stop; the station stop"
+            + " should be kept as a separate, renamed entity");
+
+    boolean foundStopTime = false;
+    for (Trip trip : dao.getAllTrips()) {
+      for (StopTime st : dao.getStopTimesForTrip(trip)) {
+        foundStopTime = true;
+        Stop mergedStop = (Stop) st.getStop();
+        assertEquals(
+            0,
+            mergedStop.getLocationType(),
+            "GTFS spec: trips must reference location_type=0 stops, not stations (location_type="
+                + mergedStop.getLocationType()
+                + ")");
+      }
+    }
+    assertTrue(foundStopTime, "expected at least one merged stop_time");
+  }
+
+  /**
+   * Same reproduction as {@link #testLocationTypeMismatch_StationFeedFirstPlatformFeedSecond}, with
+   * input order reversed: platform feed listed first (_oldGtfs), station feed listed second
+   * (_newGtfs). GtfsMerger processes the LAST listed feed first, so the station feed's stop
+   * (location_type=1) is registered as the target stop first. When the platform feed's stop
+   * (location_type=0, which owns the StopTime) is processed,
+   * StopMergeStrategy#rejectDuplicateOverDifferences rejects it as a duplicate due to the
+   * location_type mismatch, so it is kept as a separate, renamed Stop and the StopTime keeps
+   * referencing it rather than being repointed onto the station.
+   */
+  @Test
+  public void testLocationTypeMismatch_PlatformFeedFirstStationFeedSecond() throws IOException {
+    _oldGtfs.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Metro,http://metro.gov/,America/Los_Angeles");
+    _oldGtfs.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        "100,Stop 100,47.654403,-122.305211,0");
+    _oldGtfs.putLines(
+        "routes.txt", "route_id,route_short_name,route_long_name,route_type", "R1,1,Route One,3");
+    _oldGtfs.putLines(
+        "calendar.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "sid0,1,1,1,1,1,0,0,20120101,20121231");
+    _oldGtfs.putLines("trips.txt", "route_id,service_id,trip_id", "R1,sid0,T1");
+    _oldGtfs.putLines(
+        "stop_times.txt",
+        "trip_id,stop_id,stop_sequence,arrival_time,departure_time",
+        "T1,100,0,08:00:00,08:00:00");
+
+    _newGtfs.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Metro,http://metro.gov/,America/Los_Angeles");
+    _newGtfs.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        "100,Stop 100,47.654403,-122.305211,1");
+    _newGtfs.putLines("routes.txt", "route_id,route_short_name,route_long_name,route_type", "");
+    _newGtfs.putLines(
+        "calendar.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "");
+    _newGtfs.putLines("trips.txt", "route_id,service_id,trip_id", "");
+    _newGtfs.putLines(
+        "stop_times.txt", "trip_id,stop_id,stop_sequence,arrival_time,departure_time", "");
+
+    StopMergeStrategy stopStrategy = new StopMergeStrategy();
+    stopStrategy.setDuplicateDetectionStrategy(EDuplicateDetectionStrategy.IDENTITY);
+    _merger.setStopStrategy(stopStrategy);
+
+    GtfsRelationalDao dao = merge();
+
+    assertEquals(
+        2,
+        dao.getAllStops().size(),
+        "stops with incompatible location_type must not collapse into one Stop; the platform stop"
+            + " should be kept as a separate, renamed entity");
+
+    boolean foundStopTime = false;
+    for (Trip trip : dao.getAllTrips()) {
+      for (StopTime st : dao.getStopTimesForTrip(trip)) {
+        foundStopTime = true;
+        Stop mergedStop = (Stop) st.getStop();
+        assertEquals(
+            0,
+            mergedStop.getLocationType(),
+            "GTFS spec: trips must reference location_type=0 stops, not stations (location_type="
+                + mergedStop.getLocationType()
+                + ")");
+      }
+    }
+    assertTrue(foundStopTime, "expected at least one merged stop_time");
+  }
+
   private GtfsRelationalDao merge() throws IOException {
     List<File> paths = new ArrayList<>();
     paths.add(_oldGtfs.getPath());

onebusaway-gtfs-merge/src/test/java/org/onebusaway/gtfs_merge/StopLocationTypeMergeTest.java

@@ -0,0 +1,175 @@
+/**
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * <p>Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ * <p>http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * <p>Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onebusaway.gtfs_merge;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.onebusaway.gtfs.impl.GtfsRelationalDaoImpl;
+import org.onebusaway.gtfs.model.Stop;
+import org.onebusaway.gtfs.model.StopTime;
+import org.onebusaway.gtfs.serialization.GtfsReader;
+import org.onebusaway.gtfs.services.GtfsRelationalDao;
+import org.onebusaway.gtfs.services.MockGtfs;
+
+/**
+ * Reproduces <a href="https://github.com/OneBusAway/onebusaway-gtfs-modules/issues/409">issue
+ * #409</a> through the real production merge path ({@link GtfsMerger#run(List, File)}), not an
+ * isolated call to a single merge strategy.
+ *
+ * <p>Two feeds publish the same stop_id, but disagree on location_type: one models it as a platform
+ * (location_type=0) that a trip actually visits, the other models it as a station
+ * (location_type=1). Per the GTFS spec, a stop_time may only reference a stop (location_type=0),
+ * never a station. StopMergeStrategy#rejectDuplicateOverDifferences rejects a same-id pair whose
+ * location_type differs, so the two entities are never merged into one Stop; instead, whichever one
+ * is loaded second is renamed and kept as a separate entity, and stop_times always keep referencing
+ * their original location_type=0 stop.
+ */
+public class StopLocationTypeMergeTest {
+
+  private static final String STOP_ID = "1000";
+
+  /** location_type=0, visited by trip T1 via a stop_time - this is the spec-valid feed. */
+  private MockGtfs _platformFeed;
+
+  /** location_type=1, same stop_id and same location, visited by no trip of its own. */
+  private MockGtfs _stationFeed;
+
+  @BeforeEach
+  public void before() throws IOException {
+    _platformFeed = MockGtfs.create();
+    _platformFeed.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Agency,http://agency.example/,America/Los_Angeles");
+    _platformFeed.putLines(
+        "routes.txt",
+        "agency_id,route_id,route_short_name,route_long_name,route_type",
+        "1,R1,1,Route One,3");
+    _platformFeed.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        STOP_ID + ",Main St,47.6,-122.3,0");
+    _platformFeed.putLines(
+        "calendars.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "sid0,1,1,1,1,1,1,1,20250101,20251231");
+    _platformFeed.putLines("trips.txt", "route_id,service_id,trip_id", "R1,sid0,T1");
+    _platformFeed.putLines(
+        "stop_times.txt",
+        "trip_id,stop_id,stop_sequence,arrival_time,departure_time",
+        "T1," + STOP_ID + ",0,08:00:00,08:00:00");
+
+    _stationFeed = MockGtfs.create();
+    _stationFeed.putLines(
+        "agency.txt",
+        "agency_id,agency_name,agency_url,agency_timezone",
+        "1,Agency,http://agency.example/,America/Los_Angeles");
+    _stationFeed.putLines(
+        "routes.txt", "agency_id,route_id,route_short_name,route_long_name,route_type", "");
+    _stationFeed.putLines(
+        "stops.txt",
+        "stop_id,stop_name,stop_lat,stop_lon,location_type",
+        STOP_ID + ",Main St,47.6,-122.3,1");
+    _stationFeed.putLines(
+        "calendars.txt",
+        "service_id,monday,tuesday,wednesday,thursday,friday,saturday,sunday,start_date,end_date",
+        "");
+    _stationFeed.putLines("trips.txt", "route_id,service_id,trip_id", "");
+    _stationFeed.putLines(
+        "stop_times.txt", "trip_id,stop_id,stop_sequence,arrival_time,departure_time", "");
+  }
+
+  /**
+   * Station feed is listed LAST. GtfsMerger.run() walks the input path list in reverse, so the
+   * last-listed feed is loaded into the empty merge target first and would win any stop_id conflict
+   * (see GtfsMerger#run, and the "lowest priority feed (first) to highest priority feed (last)"
+   * convention documented in GtfsMergerTest) -- except that the differing location_type causes the
+   * platform feed's stop to be rejected as a duplicate and kept as a separate, renamed Stop
+   * instead.
+   */
+  @Test
+  public void testStationFeedListedLast_stopTimeEndsUpOnStation() throws IOException {
+    GtfsRelationalDao dao = merge(_platformFeed, _stationFeed);
+
+    assertEquals(
+        2,
+        dao.getAllStops().size(),
+        "stops with incompatible location_type must not collapse into one Stop; the platform stop"
+            + " should be kept as a separate, renamed entity");
+    StopTime stopTime = onlyStopTime(dao);
+    Stop mergedStop = (Stop) stopTime.getStop();
+
+    // EXPECTED (GTFS spec): a trip's stop_time must reference a stop (location_type=0),
+    // never a station (location_type=1).
+    assertEquals(
+        Stop.LOCATION_TYPE_STOP,
+        mergedStop.getLocationType(),
+        "issue #409: StopTime for trip T1 must reference the platform (location_type=0), not"
+            + " the station (location_type=1) it was merged into");
+  }
+
+  /**
+   * Same two feeds, order reversed: platform feed now listed last (highest priority), so it is the
+   * one loaded into the target first this time. Included to show that the outcome for a fixed pair
+   * of feeds flips depending purely on caller-supplied file order, not on location_type - i.e.
+   * there is no rule anywhere in the merge path that gives stations priority over stops, or vice
+   * versa.
+   */
+  @Test
+  public void testPlatformFeedListedLast_stopTimeStaysOnPlatform() throws IOException {
+    GtfsRelationalDao dao = merge(_stationFeed, _platformFeed);
+
+    assertEquals(
+        2,
+        dao.getAllStops().size(),
+        "stops with incompatible location_type must not collapse into one Stop; the station stop"
+            + " should be kept as a separate, renamed entity");
+    StopTime stopTime = onlyStopTime(dao);
+    Stop mergedStop = (Stop) stopTime.getStop();
+
+    assertEquals(
+        Stop.LOCATION_TYPE_STOP,
+        mergedStop.getLocationType(),
+        "StopTime for trip T1 should reference the platform (location_type=0)");
+  }
+
+  private StopTime onlyStopTime(GtfsRelationalDao dao) {
+    assertEquals(1, dao.getAllStopTimes().size(), "expected exactly one merged stop_time");
+    return dao.getAllStopTimes().iterator().next();
+  }
+
+  /** Runs the real GtfsMerger.run() production pipeline over the given feeds, in order. */
+  private GtfsRelationalDao merge(MockGtfs first, MockGtfs second) throws IOException {
+    List<File> paths = new ArrayList<>();
+    paths.add(first.getPath());
+    paths.add(second.getPath());
+
+    MockGtfs mergedGtfs = MockGtfs.create();
+    GtfsMerger merger = new GtfsMerger(false);
+    merger.run(paths, mergedGtfs.getPath());
+
+    GtfsReader reader = new GtfsReader();
+    GtfsRelationalDaoImpl dao = new GtfsRelationalDaoImpl();
+    reader.setEntityStore(dao);
+    reader.setInputLocation(mergedGtfs.getPath());
+    reader.run();
+    return dao;
+  }
+}