fix: mark transfer from and to stop ids as conditional required fields (

#1772)

main/src/main/java/org/mobilitydata/gtfsvalidator/table/GtfsTransferSchema.java

@@ -23,13 +23,13 @@
 @GtfsTable("transfers.txt")
 public interface GtfsTransferSchema extends GtfsEntity {
   @FieldType(FieldTypeEnum.ID)
-  @Required
+  @ConditionallyRequired
   @ForeignKey(table = "stops.txt", field = "stop_id")
   @PrimaryKey(translationRecordIdType = RECORD_ID)
   String fromStopId();
 
   @FieldType(FieldTypeEnum.ID)
-  @Required
+  @ConditionallyRequired
   @ForeignKey(table = "stops.txt", field = "stop_id")
   @PrimaryKey(translationRecordIdType = RECORD_SUB_ID)
   String toStopId();

main/src/main/java/org/mobilitydata/gtfsvalidator/validator/TransferStopIdsConditionalValidator.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2024 MobilityData
+ *
+ * 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
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.mobilitydata.gtfsvalidator.validator;
+
+import static org.mobilitydata.gtfsvalidator.table.GtfsTransferType.IN_SEAT_TRANSFER_ALLOWED;
+import static org.mobilitydata.gtfsvalidator.table.GtfsTransferType.IN_SEAT_TRANSFER_NOT_ALLOWED;
+
+import javax.inject.Inject;
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidator;
+import org.mobilitydata.gtfsvalidator.notice.MissingRequiredFieldNotice;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.table.GtfsTransfer;
+import org.mobilitydata.gtfsvalidator.table.GtfsTransferTableContainer;
+
+/**
+ * Validates the conditional requirement of {@code transfers.from_stop_id} and {@code to_stop_id}.
+ *
+ * <p>Generated notice:
+ *
+ * <ul>
+ *   <li>{@link MissingRequiredFieldNotice} - {@code from_stop_id} is missing or {@code to_stop_id}
+ *       is missing for all transfer types except for in-seat transfer types
+ * </ul>
+ */
+@GtfsValidator
+public class TransferStopIdsConditionalValidator extends FileValidator {
+
+  private final GtfsTransferTableContainer transfersContainer;
+
+  @Inject
+  public TransferStopIdsConditionalValidator(GtfsTransferTableContainer transfersContainer) {
+    this.transfersContainer = transfersContainer;
+  }
+
+  @Override
+  public void validate(NoticeContainer noticeContainer) {
+    for (GtfsTransfer transfer : transfersContainer.getEntities()) {
+      if (transfer.hasTransferType()) {
+        validateTransferEntity(transfer, noticeContainer);
+      }
+    }
+  }
+
+  private boolean isTransferTypeInSeat(GtfsTransfer transfer) {
+    return IN_SEAT_TRANSFER_ALLOWED.equals(transfer.transferType())
+        || IN_SEAT_TRANSFER_NOT_ALLOWED.equals(transfer.transferType());
+  }
+
+  private void validateTransferEntity(GtfsTransfer transfer, NoticeContainer noticeContainer) {
+    if (!isTransferTypeInSeat(transfer)) {
+      if (!transfer.hasFromStopId()) {
+        noticeContainer.addValidationNotice(
+            new MissingRequiredFieldNotice(
+                transfersContainer.gtfsFilename(), transfer.csvRowNumber(), "from_stop_id"));
+      }
+      if (!transfer.hasToStopId()) {
+        noticeContainer.addValidationNotice(
+            new MissingRequiredFieldNotice(
+                transfersContainer.gtfsFilename(), transfer.csvRowNumber(), "to_stop_id"));
+      }
+    }
+  }
+}

main/src/test/java/org/mobilitydata/gtfsvalidator/validator/TransferStopIdsConditionalValidatorTest.java

@@ -0,0 +1,97 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.ImmutableList;
+import java.util.Arrays;
+import org.junit.Before;
+import org.junit.Test;
+import org.mobilitydata.gtfsvalidator.notice.MissingRequiredFieldNotice;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.table.GtfsTransfer;
+import org.mobilitydata.gtfsvalidator.table.GtfsTransferTableContainer;
+import org.mobilitydata.gtfsvalidator.table.GtfsTransferType;
+
+public class TransferStopIdsConditionalValidatorTest {
+
+  private NoticeContainer noticeContainer;
+
+  @Before
+  public void setUp() {
+    noticeContainer = new NoticeContainer();
+  }
+
+  /**
+   * This test is used to verify that the validator does not generate a notice when the {@code
+   * from_stop_id} is missing for in-seat transfer types.
+   */
+  @Test
+  public void testTransferFromStopIdNoInSeatTransferNoNotice() {
+    //        In seat transfer types are 4 and 5, so we test for all other types
+    for (int i = 4; i <= 5; i++) {
+      GtfsTransferType transferType = GtfsTransferType.forNumber(i);
+      GtfsTransferTableContainer gtfsTransferTableContainer =
+          GtfsTransferTableContainer.forEntities(
+              ImmutableList.of(new GtfsTransfer.Builder().setTransferType(transferType).build()),
+              noticeContainer);
+
+      new TransferStopIdsConditionalValidator(gtfsTransferTableContainer).validate(noticeContainer);
+
+      assertThat(noticeContainer.getValidationNotices()).isEmpty();
+      noticeContainer.getValidationNotices().clear();
+    }
+  }
+
+  /**
+   * This test is used to verify that the validator generates a notice when the {@code from_stop_id}
+   * is missing for transfer types other than in-seat transfer types.
+   */
+  @Test
+  public void testTransferMissingFromStopIdNoInSeatTransfer() {
+    for (int i = 0; i < 4; i++) {
+      GtfsTransferType transferType = GtfsTransferType.forNumber(i);
+      GtfsTransferTableContainer gtfsTransferTableContainer =
+          GtfsTransferTableContainer.forEntities(
+              ImmutableList.of(new GtfsTransfer.Builder().setTransferType(transferType).build()),
+              noticeContainer);
+
+      new TransferStopIdsConditionalValidator(gtfsTransferTableContainer).validate(noticeContainer);
+
+      assertThat(noticeContainer.getValidationNotices()).isNotEmpty();
+      assertThat(noticeContainer.getValidationNotices())
+          .containsExactlyElementsIn(
+              Arrays.asList(
+                  new MissingRequiredFieldNotice(
+                      GtfsTransfer.FILENAME, 0, GtfsTransfer.FROM_STOP_ID_FIELD_NAME),
+                  new MissingRequiredFieldNotice(
+                      GtfsTransfer.FILENAME, 0, GtfsTransfer.TO_STOP_ID_FIELD_NAME)));
+
+      noticeContainer.getValidationNotices().clear();
+    }
+  }
+
+  /**
+   * This test is used to verify that the validator doesn't generate a notice when the {@code
+   * to_stop_id} and {@code from_stop_id} are present for all transfer types.
+   */
+  @Test
+  public void testTransferFromStopIdNoInSeatTransfer() {
+    for (int i = 0; i <= 5; i++) {
+      GtfsTransferType transferType = GtfsTransferType.forNumber(i);
+      GtfsTransferTableContainer gtfsTransferTableContainer =
+          GtfsTransferTableContainer.forEntities(
+              ImmutableList.of(
+                  new GtfsTransfer.Builder()
+                      .setFromStopId("stop1")
+                      .setToStopId("stop2")
+                      .setTransferType(transferType)
+                      .build()),
+              noticeContainer);
+
+      new TransferStopIdsConditionalValidator(gtfsTransferTableContainer).validate(noticeContainer);
+
+      assertThat(noticeContainer.getValidationNotices()).isEmpty();
+      noticeContainer.getValidationNotices().clear();
+    }
+  }
+}