feat: validate stair_count, traversal_time and max_slope against pathway_mode

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

@@ -0,0 +1,29 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidator;
+import org.mobilitydata.gtfsvalidator.notice.MissingRecommendedFieldNotice;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathway;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathwayMode;
+
+/**
+ * Validates that {@code stair_count} is provided for pathways that are stairs.
+ *
+ * <p>The GTFS specification recommends {@code pathways.stair_count} for stairs ({@code
+ * pathway_mode=2}). Without it, a consumer cannot tell how many steps a path involves, which is
+ * information riders with limited mobility rely on when choosing a route through a station.
+ *
+ * <p>Generated notice: {@link MissingRecommendedFieldNotice}.
+ */
+@GtfsValidator
+public class PathwayStairCountValidator extends SingleEntityValidator<GtfsPathway> {
+
+  @Override
+  public void validate(GtfsPathway entity, NoticeContainer noticeContainer) {
+    if (entity.pathwayMode() == GtfsPathwayMode.STAIRS && !entity.hasStairCount()) {
+      noticeContainer.addValidationNotice(
+          new MissingRecommendedFieldNotice(
+              GtfsPathway.FILENAME, entity.csvRowNumber(), GtfsPathway.STAIR_COUNT_FIELD_NAME));
+    }
+  }
+}

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

@@ -0,0 +1,63 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mobilitydata.gtfsvalidator.notice.MissingRecommendedFieldNotice;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.notice.ValidationNotice;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathway;
+import org.mobilitydata.gtfsvalidator.table.GtfsPathwayMode;
+
+@RunWith(JUnit4.class)
+public class PathwayStairCountValidatorTest {
+
+  @Test
+  public void stairsWithoutStairCount_yieldsNotice() {
+    assertThat(validationNoticesFor(pathwayBuilder(GtfsPathwayMode.STAIRS).build()))
+        .containsExactly(new MissingRecommendedFieldNotice("pathways.txt", 2, "stair_count"));
+  }
+
+  @Test
+  public void stairsWithStairCount_yieldsNoNotice() {
+    assertThat(
+            validationNoticesFor(pathwayBuilder(GtfsPathwayMode.STAIRS).setStairCount(5).build()))
+        .isEmpty();
+  }
+
+  @Test
+  public void stairsWithNegativeStairCount_yieldsNoNotice() {
+    // stair_count is signed: a negative value describes a descending path, so it is still defined.
+    assertThat(
+            validationNoticesFor(pathwayBuilder(GtfsPathwayMode.STAIRS).setStairCount(-5).build()))
+        .isEmpty();
+  }
+
+  @Test
+  public void nonStairsWithoutStairCount_yieldsNoNotice() {
+    for (GtfsPathwayMode mode : GtfsPathwayMode.values()) {
+      if (mode == GtfsPathwayMode.STAIRS) {
+        continue;
+      }
+      assertThat(validationNoticesFor(pathwayBuilder(mode).build())).isEmpty();
+    }
+  }
+
+  private static GtfsPathway.Builder pathwayBuilder(GtfsPathwayMode pathwayMode) {
+    return new GtfsPathway.Builder()
+        .setCsvRowNumber(2)
+        .setPathwayId("pathway1")
+        .setFromStopId("stop1")
+        .setToStopId("stop2")
+        .setPathwayMode(pathwayMode);
+  }
+
+  private static List<ValidationNotice> validationNoticesFor(GtfsPathway entity) {
+    NoticeContainer noticeContainer = new NoticeContainer();
+    new PathwayStairCountValidator().validate(entity, noticeContainer);
+    return noticeContainer.getValidationNotices();
+  }
+}