Merge pull request #416 from weaviate/v6-aggregate-groupby-limit

v6: Add `limit` to GroupBy parameter in Aggregate queries

Author: bevzzz

src/it/java/io/weaviate/integration/AggregationITest.java

@@ -80,7 +80,7 @@ public void testOverAll_groupBy_category() {
                 Aggregation.integer("price",
                     calculate -> calculate.min().max().count()))
             .includeTotalCount(true),
-        new GroupBy("category"));
+        GroupBy.property("category"));
 
     Assertions.assertThat(result)
         .extracting(AggregateResponseGrouped::groups)
@@ -139,7 +139,7 @@ public void testNearVector_groupBy_category() {
                     calculate -> calculate.min().max().median()))
             .objectLimit(9)
             .includeTotalCount(true),
-        new GroupBy("category"));
+        GroupBy.property("category"));
 
     Assertions.assertThat(result)
         .extracting(AggregateResponseGrouped::groups)

src/main/java/io/weaviate/client6/v1/api/collections/aggregate/GroupBy.java

@@ -1,13 +1,48 @@
 package io.weaviate.client6.v1.api.collections.aggregate;
 
+import java.util.function.Function;
+
+import io.weaviate.client6.v1.internal.ObjectBuilder;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoAggregate;
 
-public record GroupBy(String property) {
-  public static final GroupBy of(String property) {
-    return new GroupBy(property);
+public record GroupBy(String property, Integer limit) {
+  public static final GroupBy property(String property) {
+    return property(property, ObjectBuilder.identity());
+  }
+
+  public static final GroupBy property(String property, Function<Builder, ObjectBuilder<GroupBy>> fn) {
+    return fn.apply(new Builder(property)).build();
+  }
+
+  public GroupBy(Builder builder) {
+    this(builder.property, builder.limit);
+  }
+
+  public static class Builder implements ObjectBuilder<GroupBy> {
+    private final String property;
+
+    public Builder(String property) {
+      this.property = property;
+    }
+
+    private Integer limit;
+
+    public final Builder limit(int limit) {
+      this.limit = limit;
+      return this;
+    }
+
+    @Override
+    public GroupBy build() {
+      return new GroupBy(this);
+    }
   }
 
   void appendTo(WeaviateProtoAggregate.AggregateRequest.Builder req, String collection) {
+    if (limit != null) {
+      req.setLimit(limit);
+    }
+
     req.setGroupBy(WeaviateProtoAggregate.AggregateRequest.GroupBy.newBuilder()
         .setCollection(collection)
         .setProperty(property));