refactor: factor out marshaling a Struct

This is done 3 times:
1. High-level properties
2. Map<String, Object>
3. Custom records

Author: bevzzz

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

@@ -486,7 +486,7 @@ public void testNestedProperties_insertMany() throws IOException {
                 Property.integer("buildingNr"),
                 Property.bool("isOneWay")))));
 
-    var buildings = client.collections.use("nsBuildings");
+    var buildings = client.collections.use(nsBuildings);
 
     Map<String, Object> house_1 = Map.of("address", Map.of(
         "street", "Burggasse",

src/main/java/io/weaviate/client6/v1/api/collections/data/InsertManyRequest.java

@@ -130,25 +130,9 @@ public static <T> void buildObject(WeaviateProtoBatch.BatchObject.Builder object
       }
     }
 
-    var properties = WeaviateProtoBatch.BatchObject.Properties.newBuilder();
-    var nonRef = com.google.protobuf.Struct.newBuilder();
     var singleRef = new ArrayList<WeaviateProtoBatch.BatchObject.SingleTargetRefProps>();
     var multiRef = new ArrayList<WeaviateProtoBatch.BatchObject.MultiTargetRefProps>();
 
-    collection
-        .propertiesReader(insert.properties()).readProperties()
-        .entrySet().stream().forEach(entry -> {
-          try {
-            var protoValue = marshalValue(entry.getValue());
-            if (protoValue == null) {
-              return;
-            }
-            nonRef.putFields(entry.getKey(), protoValue);
-          } catch (IllegalArgumentException e) {
-            throw new IllegalArgumentException("marshal property " + entry.getKey(), e);
-          }
-        });
-
     insert.references()
         .entrySet().stream().forEach(entry -> {
           var references = entry.getValue();
@@ -173,16 +157,16 @@ public static <T> void buildObject(WeaviateProtoBatch.BatchObject.Builder object
           }
         });
 
-    properties
+    var nonRef = marshalStruct(collection.propertiesReader(insert.properties()).readProperties());
+    object.setProperties(WeaviateProtoBatch.BatchObject.Properties.newBuilder()
         .setNonRefProperties(nonRef)
         .addAllSingleTargetRefProps(singleRef)
-        .addAllMultiTargetRefProps(multiRef);
-
-    object.setProperties(properties);
+        .addAllMultiTargetRefProps(multiRef));
 
     Debug.printProto(object);
   }
 
+  @SuppressWarnings("unchecked")
   private static com.google.protobuf.Value marshalValue(Object value) {
     var protoValue = com.google.protobuf.Value.newBuilder();
 
@@ -282,35 +266,30 @@ private static com.google.protobuf.Value marshalValue(Object value) {
       protoValue.setListValue(com.google.protobuf.ListValue.newBuilder()
           .addAllValues(values)
           .build());
-    } else if (value instanceof Map<?, ?> v) {
-      var protoNested = com.google.protobuf.Struct.newBuilder();
-      v.entrySet().stream()
-          .forEach(nested -> {
-            var nestedValue = marshalValue(nested.getValue());
-            if (nestedValue == null) {
-              return;
-            }
-            protoNested.putFields((String) nested.getKey(), nestedValue);
-          });
-      protoValue.setStructValue(protoNested);
+    } else if (value instanceof Map<?, ?> properties) {
+      protoValue.setStructValue(marshalStruct((Map<String, Object>) properties));
     } else if (value instanceof Record r) {
-      @SuppressWarnings("unchecked")
       CollectionDescriptor<? super Record> recordDescriptor = (CollectionDescriptor<? super Record>) CollectionDescriptor
           .ofClass(r.getClass());
-      var protoRecord = com.google.protobuf.Struct.newBuilder();
-      recordDescriptor.propertiesReader(r).readProperties().entrySet().stream()
-          .forEach(recordField -> {
-            var nestedValue = marshalValue(recordField.getValue());
-            if (nestedValue == null) {
-              return;
-            }
-            protoRecord.putFields((String) recordField.getKey(), nestedValue);
-          });
-      protoValue.setStructValue(protoRecord);
+      var properties = recordDescriptor.propertiesReader(r).readProperties();
+      protoValue.setStructValue(marshalStruct(properties));
     } else {
       throw new IllegalArgumentException("data type " + value.getClass() + " is not supported");
     }
 
     return protoValue.build();
   }
+
+  private static com.google.protobuf.Struct marshalStruct(Map<String, Object> properties) {
+    var struct = com.google.protobuf.Struct.newBuilder();
+    properties.entrySet().stream()
+        .forEach(entry -> {
+          var nestedValue = marshalValue(entry.getValue());
+          if (nestedValue == null) {
+            return;
+          }
+          struct.putFields((String) entry.getKey(), nestedValue);
+        });
+    return struct.build();
+  }
 }