new rule for shapes with single shape point

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

@@ -0,0 +1,70 @@
+package org.mobilitydata.gtfsvalidator.validator;
+
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidationNotice;
+import org.mobilitydata.gtfsvalidator.annotation.GtfsValidator;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.notice.ValidationNotice;
+import org.mobilitydata.gtfsvalidator.table.GtfsShape;
+import org.mobilitydata.gtfsvalidator.table.GtfsShapeSchema;
+import org.mobilitydata.gtfsvalidator.table.GtfsShapeTableContainer;
+
+import javax.inject.Inject;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.mobilitydata.gtfsvalidator.notice.SeverityLevel.WARNING;
+
+/**
+ * Validates that every shape (identified by shape_id) has more than one shape_point
+ *
+ * <p>Generated notice: {@link SingleShapePointNotice}</p>
+ */
+@GtfsValidator
+public class SingleShapePointValidator extends FileValidator {
+    private final GtfsShapeTableContainer shapeTable;
+
+    @Inject
+    SingleShapePointValidator(GtfsShapeTableContainer shapeTable){
+        this.shapeTable = shapeTable;
+    }
+
+    @Override
+    public void validate(NoticeContainer noticeContainer) {
+        Map<String, Integer> shapePointCounts = new HashMap<>();
+        Map<String, Integer> shapePointRowNumbers = new HashMap<>();
+        for (GtfsShape shape : shapeTable.getEntities()) {
+            String shapeId = shape.shapeId();
+            shapePointCounts.put(shapeId, shapePointCounts.getOrDefault(shapeId, 0) + 1);
+            shapePointRowNumbers.put(shapeId, shape.csvRowNumber());
+        }
+
+        for (Map.Entry<String, Integer> entry : shapePointCounts.entrySet()) {
+            if (entry.getValue() == 1) {
+                noticeContainer.addValidationNotice(new SingleShapePointNotice(entry.getKey(),shapePointRowNumbers.getOrDefault(entry.getKey(),0)));
+            }
+        }
+    }
+
+    /**
+     * The shape within `shapes.txt` contains a single shape point.
+     *
+     * <p>A shape should contain more than one shape point to visualize the route on any GIS software (which require LineString).</p>
+     */
+    @GtfsValidationNotice(
+            severity = WARNING,
+            files = @GtfsValidationNotice.FileRefs({GtfsShapeSchema.class})
+    )
+
+    static class SingleShapePointNotice extends ValidationNotice {
+        /** The faulty record's id. */
+        private final String shapeId;
+
+        /** The row number of the faulty record. */
+        private final int csvRowNumber;
+
+        SingleShapePointNotice(String shapeId, int csvRowNumber) {
+            this.shapeId = shapeId;
+            this.csvRowNumber = csvRowNumber;
+        }
+    }
+}

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

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+package org.mobilitydata.gtfsvalidator.validator;
+
+import com.google.common.collect.ImmutableList;
+import org.junit.Test;
+import org.mobilitydata.gtfsvalidator.notice.NoticeContainer;
+import org.mobilitydata.gtfsvalidator.notice.ValidationNotice;
+import org.mobilitydata.gtfsvalidator.table.GtfsShape;
+import org.mobilitydata.gtfsvalidator.table.GtfsShapeTableContainer;
+
+import java.util.List;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class SingleShapePointValidatorTest {
+    public static GtfsShape createShapePoint(
+            int csvRowNumber,
+            String shapeId,
+            double shapePtLat,
+            double shapePtLon,
+            int shapePtSequence,
+            double shapeDistTraveled) {
+        return new GtfsShape.Builder()
+                .setCsvRowNumber(csvRowNumber)
+                .setShapeId(shapeId)
+                .setShapePtLat(shapePtLat)
+                .setShapePtLon(shapePtLon)
+                .setShapePtSequence(shapePtSequence)
+                .setShapeDistTraveled(shapeDistTraveled)
+                .build();
+    }
+
+
+    private static List<ValidationNotice> generateNotices(
+            List<GtfsShape> shapes) {
+        NoticeContainer noticeContainer = new NoticeContainer();
+        new SingleShapePointValidator(
+                GtfsShapeTableContainer.forEntities(shapes, noticeContainer))
+                .validate(noticeContainer);
+        return noticeContainer.getValidationNotices();
+    }
+
+    @Test
+    public void shapeWithMoreThanOneShapePointShouldNotGenerateNotice() {
+        assertThat(
+                generateNotices(
+                        ImmutableList.of(
+                                createShapePoint(1, "first shape id", 45.0d, 45.0d, 1, 0.0d),
+                                createShapePoint(2, "first shape id", 45.1d, 45.0d, 2, 40.0d)
+                        ))
+        ).isEmpty();
+    }
+
+    @Test
+    public void unusedShapeShouldGenerateNotice() {
+        assertThat(
+                generateNotices(
+                        ImmutableList.of(
+                                createShapePoint(1, "first shape id", 45.0d, 45.0d, 1, 40.0d),
+                                createShapePoint(2, "first shape id", 45.1d, 45.0d, 2, 40.0d),
+                                createShapePoint(3, "second shape id", 45.0d, 45.0d, 1, 40.0d)))
+                ).containsExactly(new SingleShapePointValidator.SingleShapePointNotice("second shape id", 3));
+    }
+}