feat: 1786 exit gates pathway mode7 must not be bidirectional (#1808)

* added PathwayBidirectionalExitGatesValidator

* used SingleEntityValidator; fixed a typo in NoticeDocumentationTest

* added class comment and field comments

* fixed broken NoticeFieldsTest

* added PathwayBidirectionalExitGatesValidatorTest

* renamed validator and notice

* formatted code

* renamed notice from plural to singular gate

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

@@ -0,0 +1,49 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import static org.mobilitydata.gtfsvalidator.notice.SeverityLevel.ERROR;
+
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidationNotice;
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidationNotice.FileRefs;
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidator;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.notice.ValidationNotice;
+import org.mobilitydata.gtfsvalidator.table.*;
+
+/**
+ * Validates that:
+ *
+ * <ul>
+ *   <li>Exit gates (pathway_mode=7) must not be bidirectional.
+ * </ul>
+ */
+@GtfsValidator
+public class BidirectionalExitGateValidator extends SingleEntityValidator<GtfsPathway> {
+
+  @Override
+  public void validate(GtfsPathway entity, NoticeContainer noticeContainer) {
+    if (entity.pathwayMode().getNumber() == 7 && entity.isBidirectional().getNumber() == 1) {
+      noticeContainer.addValidationNotice(new BidirectionalExitGateNotice(entity));
+    }
+  }
+
+  /**
+   * Pathway is bidirectional and has mode 7 (exit gate).
+   *
+   * <p>Exit gates (pathway_mode=7) must not be bidirectional.
+   */
+  @GtfsValidationNotice(severity = ERROR, files = @FileRefs({GtfsPathwaySchema.class}))
+  static class BidirectionalExitGateNotice extends ValidationNotice {
+    /** The row number of the validated record. */
+    private final int csvRowNumber;
+    /** The pathway mode. */
+    private final int pathwayMode;
+    /** Whether the pathway is bidirectional. */
+    private final int isBidirectional;
+
+    BidirectionalExitGateNotice(GtfsPathway pathway) {
+      this.csvRowNumber = pathway.csvRowNumber();
+      this.pathwayMode = pathway.pathwayMode().getNumber();
+      this.isBidirectional = pathway.isBidirectional().getNumber();
+    }
+  }
+}

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

@@ -0,0 +1,42 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathway;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathwayIsBidirectional;
+
+@RunWith(JUnit4.class)
+public class BidirectionalExitGateValidatorTest {
+  public static GtfsPathway createPathway(
+      int csvRowNumber,
+      Integer pathwayMode,
+      GtfsPathwayIsBidirectional gtfsPathwayIsBidirectional) {
+    return new GtfsPathway.Builder()
+        .setCsvRowNumber(csvRowNumber)
+        .setPathwayMode(pathwayMode)
+        .setIsBidirectional(gtfsPathwayIsBidirectional)
+        .build();
+  }
+
+  /** Tests that a pathway with bidirectional exit gates generates a notice. */
+  @Test
+  public void isBidirectionalExitGateShouldGenerateNotice() {
+    GtfsPathway entity = createPathway(1, 7, GtfsPathwayIsBidirectional.BIDIRECTIONAL);
+    NoticeContainer noticeContainer = new NoticeContainer();
+    new BidirectionalExitGateValidator().validate(entity, noticeContainer);
+    assertThat(noticeContainer.getValidationNotices())
+        .containsExactly(new BidirectionalExitGateValidator.BidirectionalExitGateNotice(entity));
+  }
+
+  @Test
+  public void isNotBidirectionalExitGateShouldNotGenerateNotice() {
+    GtfsPathway entity = createPathway(1, 7, GtfsPathwayIsBidirectional.UNIDIRECTIONAL);
+    NoticeContainer noticeContainer = new NoticeContainer();
+    new BidirectionalExitGateValidator().validate(entity, noticeContainer);
+    assertThat(noticeContainer.getValidationNotices()).isEmpty();
+  }
+}

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

@@ -115,7 +115,7 @@ public void testThatNoticeFieldsAreDocumented() {
             .map(f -> f.getDeclaringClass().getSimpleName() + "." + f.getName())
             .collect(Collectors.toList());
     assertWithMessage(
-            "Every field of a validation notice much be documented with a JavaDoc comment (aka /** */, not //).  The following fields are undocumented:")
+            "Every field of a validation notice must be documented with a JavaDoc comment (aka /** */, not //).  The following fields are undocumented:")
         .that(fieldsWithoutComments)
         .isEmpty();
   }

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

@@ -195,7 +195,9 @@ public void testNoticeClassFieldNames() {
             "maxShapeDistanceTraveled",
             "maxTripDistanceTraveled",
             "fileNameA",
-            "fileNameB");
+            "fileNameB",
+            "pathwayMode",
+            "isBidirectional");
   }
 
   private static List<String> discoverValidationNoticeFieldNames() {