minor fixes

Author: wu-hui

google-cloud-firestore/src/main/java/com/google/cloud/firestore/PipelineUtils.java

@@ -161,13 +161,13 @@ static Pipeline toPaginatedPipeline(
   @InternalApi
   static AggregatorTarget toPipelineAggregatorTarget(AggregateField f) {
     String operator = f.getOperator();
-    String fieldPath = f.getFieldPath(); // Assuming you have a method to get FieldPath
+    String fieldPath = f.getFieldPath();
 
     switch (operator) {
       case "sum":
         return Field.of(fieldPath)
             .sum()
-            .toField(f.getAlias()); // Note: 'toField' is assumed to be a method in your context
+            .toField(f.getAlias());
 
       case "count":
         return countAll().toField(f.getAlias());

google-cloud-firestore/src/main/java/com/google/cloud/firestore/Query.java

@@ -2160,7 +2160,7 @@ public Pipeline toPipeline() {
     }
 
     // Cursors, Limit and Offset
-    if (this.options.getStartCursor() != null || this.options.getEndCursor() != null) {
+    if (this.options.getStartCursor() != null || this.options.getEndCursor() != null || this.options.getLimitType() == LimitType.Last) {
       ppl =
           toPaginatedPipeline(
               ppl,

google-cloud-firestore/src/main/java/com/google/cloud/firestore/pipeline/stages/FindNearest.java

@@ -106,13 +106,13 @@ public static class FindNearestOptions {
 
     private final Long limit;
     private final FindNearest.DistanceMeasure distanceMeasure;
-    private final Field output;
+    private final Field distanceField;
 
     private FindNearestOptions(
-        Long limit, FindNearest.DistanceMeasure distanceMeasure, Field output) {
+        Long limit, FindNearest.DistanceMeasure distanceMeasure, Field distanceField) {
       this.limit = limit;
       this.distanceMeasure = distanceMeasure;
-      this.output = output;
+      this.distanceField = distanceField;
     }
 
     public static FindNearest.FindNearestOptions newInstance(
@@ -128,8 +128,8 @@ public DistanceMeasure getDistanceMeasure() {
       return distanceMeasure;
     }
 
-    public Field getOutput() {
-      return output;
+    public Field getDistanceField() {
+      return distanceField;
     }
   }
 }

google-cloud-firestore/src/main/java/com/google/cloud/firestore/pipeline/stages/StageUtils.java

@@ -94,7 +94,7 @@ public static com.google.firestore.v1.Pipeline.Stage toStageProto(Stage stage) {
           .addArgs(encodeValue(findNearestStage.getVector()))
           .addArgs(encodeValue(findNearestStage.getOptions().getDistanceMeasure().toProtoString()))
           .putOptions("limit", encodeValue(findNearestStage.getOptions().getLimit()))
-          .putOptions("distance_field", encodeValue(findNearestStage.getOptions().getOutput()))
+          .putOptions("distance_field", encodeValue(findNearestStage.getOptions().getDistanceField()))
           .build();
     } else if (stage instanceof GenericStage) {
       GenericStage genericStage = (GenericStage) stage;