DATAMONGO-893 - Converter must not write "_class" information for know types.

We now actively pass on property type information to MetadataBackedField to ensure type hints get picked up correctly when converting a value to the according DBObject.

This has to be done as the fix for DATAMONGO-812 enforced proper writing of _class information for Updates, which caused trouble when querying documents by nested (complex) properties using an 'in' clause.

Original pull request: #169.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java

@@ -956,7 +956,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			return getPotentiallyConvertedSimpleWrite(obj);
 		}
 
-		TypeInformation<?> typeHint = typeInformation == null ? null : ClassTypeInformation.OBJECT;
+		TypeInformation<?> typeHint = typeInformation == null ? ClassTypeInformation.OBJECT : typeInformation;
 
 		if (obj instanceof BasicDBList) {
 			return maybeConvertList((BasicDBList) obj, typeHint);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/QueryMapper.java

@@ -306,7 +306,7 @@ public class QueryMapper {
 	 * @return the converted mongo type or null if source is null
 	 */
 	protected Object delegateConvertToMongoType(Object source, MongoPersistentEntity<?> entity) {
-		return converter.convertToMongoType(source);
+		return converter.convertToMongoType(source, entity == null ? null : entity.getTypeInformation());
 	}
 
 	protected Object convertAssociation(Object source, Field field) {
@@ -611,6 +611,21 @@ public class QueryMapper {
 		 */
 		public MetadataBackedField(String name, MongoPersistentEntity<?> entity,
 				MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context) {
+			this(name, entity, context, null);
+		}
+
+		/**
+		 * Creates a new {@link MetadataBackedField} with the given name, {@link MongoPersistentEntity} and
+		 * {@link MappingContext} with the given {@link MongoPersistentProperty}.
+		 * 
+		 * @param name must not be {@literal null} or empty.
+		 * @param entity must not be {@literal null}.
+		 * @param context must not be {@literal null}.
+		 * @param property may be {@literal null}.
+		 */
+		public MetadataBackedField(String name, MongoPersistentEntity<?> entity,
+				MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> context,
+				MongoPersistentProperty property) {
 
 			super(name);
 
@@ -620,7 +635,7 @@ public class QueryMapper {
 			this.mappingContext = context;
 
 			this.path = getPath(name);
-			this.property = path == null ? null : path.getLeafProperty();
+			this.property = path == null ? property : path.getLeafProperty();
 			this.association = findAssociation();
 		}
 
@@ -630,7 +645,7 @@ public class QueryMapper {
 		 */
 		@Override
 		public MetadataBackedField with(String name) {
-			return new MetadataBackedField(name, entity, mappingContext);
+			return new MetadataBackedField(name, entity, mappingContext, property);
 		}
 
 		/*

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java

@@ -1390,6 +1390,7 @@ public class MappingMongoConverterUnitTests {
 
 	/**
 	 * @see DATAMONGO-812
+	 * @see DATAMONGO-893
 	 */
 	@Test
 	public void convertsListToBasicDBListAndRetainsTypeInformationForComplexObjects() {
@@ -1399,7 +1400,7 @@ public class MappingMongoConverterUnitTests {
 		address.street = "Foo";
 
 		Object result = converter.convertToMongoType(Collections.singletonList(address),
-				ClassTypeInformation.from(Address.class));
+				ClassTypeInformation.from(InterfaceType.class));
 
 		assertThat(result, is(instanceOf(BasicDBList.class)));
 
@@ -1554,7 +1555,11 @@ public class MappingMongoConverterUnitTests {
 		abstract void method();
 	}
 
-	static class Address {
+	static interface InterfaceType {
+
+	}
+
+	static class Address implements InterfaceType {
 		String street;
 		String city;
 	}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/QueryMapperUnitTests.java

@@ -39,6 +39,7 @@ import org.springframework.data.mongodb.core.DBObjectTestUtils;
 import org.springframework.data.mongodb.core.Person;
 import org.springframework.data.mongodb.core.mapping.BasicMongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.DBRef;
+import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
@@ -568,10 +569,42 @@ public class QueryMapperUnitTests {
 		assertThat(mappedFields, is(notNullValue()));
 	}
 
+	/**
+	 * @see DATAMONGO-893
+	 */
+	@Test
+	public void classInformationShouldNotBePresentInDBObjectUsedInFinderMethods() {
+
+		EmbeddedClass embedded = new EmbeddedClass();
+		embedded.id = "1";
+
+		EmbeddedClass embedded2 = new EmbeddedClass();
+		embedded2.id = "2";
+		Query query = query(where("embedded").in(Arrays.asList(embedded, embedded2)));
+
+		DBObject dbo = mapper.getMappedObject(query.getQueryObject(), context.getPersistentEntity(Foo.class));
+		assertThat(dbo.toString(), equalTo("{ \"embedded\" : { \"$in\" : [ { \"_id\" : \"1\"} , { \"_id\" : \"2\"}]}}"));
+	}
+
+	@Document
+	public class Foo {
+		@Id private ObjectId id;
+		EmbeddedClass embedded;
+	}
+
+	public class EmbeddedClass {
+		public String id;
+	}
+
 	class IdWrapper {
 		Object id;
 	}
 
+	class ClassWithEmbedded {
+		@Id String id;
+		Sample sample;
+	}
+
 	class ClassWithDefaultId {
 
 		String id;

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java

@@ -739,7 +739,7 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 		assertThat(result.size(), is(1));
 		assertThat(result.get(0), is(dave));
 	}
-	
+
 	/**
 	 * @see DATAMONGO-871
 	 */
@@ -751,8 +751,7 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 		assertThat(result, is(arrayWithSize(1)));
 		assertThat(result, is(arrayContaining(leroi)));
 	}
-	
-	
+
 	/**
 	 * @see DATAMONGO-821
 	 */
@@ -772,4 +771,21 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 		assertThat(result.getNumberOfElements(), is(1));
 		assertThat(result.getContent().get(0), is(alicia));
 	}
+	
+	/**
+	 * @see DATAMONGO-893
+	 */
+	@Test
+	public void findByNestedPropertyInCollectionShouldFindMatchingDocuments() {
+
+		Person p = new Person("Mary", "Poppins");
+		Address adr = new Address("some", "2", "where");
+		p.setAddress(adr);
+
+		repository.save(p);
+
+		Page<Person> result = repository.findByAddressIn(Arrays.asList(adr), new PageRequest(0, 10));
+
+		assertThat(result.getContent(), hasSize(1));
+	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/PersonRepository.java

@@ -251,10 +251,15 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	 * @see DATAMONGO-770
 	 */
 	List<Person> findByFirstnameContainingIgnoreCase(String firstName);
-	
+
 	/**
 	 * @see DATAMONGO-821
 	 */
 	@Query("{ creator : { $exists : true } }")
 	Page<Person> findByHavingCreator(Pageable page);
+
+	/**
+	 * @see DATAMONGO-893
+	 */
+	Page<Person> findByAddressIn(List<Address> address, Pageable page);
 }