fix: handle missing primitive values in ORM

Author: bevzzz

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

@@ -1,5 +1,6 @@
 package io.weaviate.integration;
 
+import java.io.IOException;
 import java.time.OffsetDateTime;
 import java.util.List;
 import java.util.Map;
@@ -14,6 +15,7 @@
 import io.weaviate.ConcurrentTest;
 import io.weaviate.client6.v1.api.WeaviateClient;
 import io.weaviate.client6.v1.api.collections.CollectionConfig;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
 import io.weaviate.client6.v1.api.collections.annotations.Collection;
 import io.weaviate.client6.v1.api.collections.annotations.Property;
 import io.weaviate.client6.v1.api.collections.data.InsertManyResponse.InsertObject;
@@ -23,7 +25,7 @@
 public class ORMITest extends ConcurrentTest {
   private static WeaviateClient client = Container.WEAVIATE.getClient();
 
-  @Collection("ORMITest")
+  @Collection("ORMITestThings")
   static record Thing(
       // text / text[]
       String text,
@@ -95,7 +97,7 @@ public void test_createCollection() throws Exception {
 
     // Assert
     Assertions.assertThat(config).get()
-        .returns("ORMITest", CollectionConfig::collectionName)
+        .returns("ORMITestThings", CollectionConfig::collectionName)
         .extracting(CollectionConfig::properties,
             InstanceOfAssertFactories.list(io.weaviate.client6.v1.api.collections.Property.class))
         .extracting(p -> Map.entry(
@@ -307,4 +309,45 @@ public void test_insertManyAndQuery() throws Exception {
         .usingRecursiveComparison(COMPARISON_CONFIG)
         .asInstanceOf(InstanceOfAssertFactories.list(Thing.class));
   }
+
+  @Collection("ORMITestSongs")
+  record Song(
+      String title,
+      String album,
+      int year,
+      boolean hasAward,
+      Long monthlyListeners) {
+  }
+
+  /**
+   * Test that serialization works correctly when some fields are null and
+   * deserialization works correctly when some properties are not returned.
+   */
+  @Test
+  public void test_partialScan() throws IOException {
+    client.collections.create(Song.class);
+
+    var songs = client.collections.use(Song.class);
+
+    // Act: insert with nulls
+    var dystopia = songs.data.insert(new Song(
+        "Dystopia",
+        null,
+        2016,
+        true,
+        null));
+
+    // Act: return subset of the properties
+    var got = songs.query.byId(dystopia.uuid(),
+        q -> q.returnProperties("title", "hasAward"));
+
+    // Assert
+    Assertions.assertThat(got).get()
+        .extracting(WeaviateObject::properties)
+        .returns("Dystopia", Song::title)
+        .returns(null, Song::album)
+        .returns(0, Song::year)
+        .returns(true, Song::hasAward)
+        .returns(null, Song::monthlyListeners);
+  }
 }

src/main/java/io/weaviate/client6/v1/internal/orm/PojoBuilder.java

@@ -19,6 +19,28 @@ static record Arg(Class<?> type, Object value) {
     Arg withValue(Object value) {
       return new Arg(this.type, value);
     }
+
+    public Object value() {
+      if (value != null) {
+        return value;
+      }
+
+      if (type == boolean.class) {
+        return false;
+      } else if (type == short.class) {
+        return (short) 0;
+      } else if (type == int.class) {
+        return 0;
+      } else if (type == long.class) {
+        return 0L;
+      } else if (type == float.class) {
+        return 0f;
+      } else if (type == double.class) {
+        return 0d;
+      }
+
+      throw new IllegalArgumentException(type.getName() + " property data type is not supported");
+    }
   }
 
   PojoBuilder(PojoDescriptor<PropertiesT> descriptor) {