DATAMONGO-969 - Fixed nested id handling in SpringDataMongodbSerializer.

SpringDataMongodbSerializer now defensively triggers mapping of the DBObject created by the default serializer. This asserts that ids buried in nested structures like { "_id" : { "$in" : ["x", "y"] } } are converted correctly.

Original pull request: #202.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/SpringDataMongodbSerializer.java

@@ -41,6 +41,8 @@ import com.mysema.query.types.PathType;
  */
 class SpringDataMongodbSerializer extends MongodbSerializer {
 
+	private final String ID_KEY = "_id";
+
 	private final MongoConverter converter;
 	private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
 	private final QueryMapper mapper;
@@ -84,8 +86,8 @@ class SpringDataMongodbSerializer extends MongodbSerializer {
 	@Override
 	protected DBObject asDBObject(String key, Object value) {
 
-		if ("_id".equals(key)) {
-			return super.asDBObject(key, mapper.convertId(value));
+		if (ID_KEY.equals(key)) {
+			return mapper.getMappedObject(super.asDBObject(key, value), null);
 		}
 
 		return super.asDBObject(key, value instanceof Pattern ? value : converter.convertToMongoType(value));

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

@@ -990,4 +990,12 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 
 		assertThat(repository.findOne(QPerson.person.creator.eq(user)), is(dave));
 	}
+	
+	/**
+	 * @see DATAMONGO-969
+	 */
+	@Test
+	public void shouldFindPersonsWhenUsingQueryDslPerdicatedOnIdProperty() {
+		assertThat(repository.findAll(person.id.in(Arrays.asList(dave.id, carter.id))), containsInAnyOrder(dave, carter));
+	}
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2013 the original author or authors.
+ * Copyright 2011-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,8 +17,10 @@ package org.springframework.data.mongodb.repository.support;
 
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
+import static org.springframework.data.mongodb.core.DBObjectTestUtils.*;
 
 import org.bson.types.ObjectId;
+import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -32,6 +34,7 @@ import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.repository.QAddress;
 import org.springframework.data.mongodb.repository.QPerson;
 
+import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
 import com.mysema.query.types.expr.BooleanOperation;
@@ -43,6 +46,7 @@ import com.mysema.query.types.path.StringPath;
  * Unit tests for {@link SpringDataMongodbSerializer}.
  * 
  * @author Oliver Gierke
+ * @author Christoph Strobl
  */
 @RunWith(MockitoJUnitRunner.class)
 public class SpringDataMongodbSerializerUnitTests {
@@ -132,6 +136,41 @@ public class SpringDataMongodbSerializerUnitTests {
 		assertThat(path, is("0"));
 	}
 
+	/**
+	 * @see DATAMONGO-969
+	 */
+	@Test
+	public void shouldConvertObjectIdEvenWhenNestedInOperatorDbObject() {
+
+		ObjectId value = new ObjectId("53bb9fd14438765b29c2d56e");
+		DBObject serialized = serializer.asDBObject("_id", new BasicDBObject("$ne", value.toString()));
+
+		DBObject _id = getAsDBObject(serialized, "_id");
+		ObjectId $ne = getTypedValue(_id, "$ne", ObjectId.class);
+		assertThat($ne, is(value));
+	}
+
+	/**
+	 * @see DATAMONGO-969
+	 */
+	@Test
+	public void shouldConvertCollectionOfObjectIdEvenWhenNestedInOperatorDbObject() {
+
+		ObjectId firstId = new ObjectId("53bb9fd14438765b29c2d56e");
+		ObjectId secondId = new ObjectId("53bb9fda4438765b29c2d56f");
+
+		BasicDBList objectIds = new BasicDBList();
+		objectIds.add(firstId.toString());
+		objectIds.add(secondId.toString());
+
+		DBObject serialized = serializer.asDBObject("_id", new BasicDBObject("$in", objectIds));
+
+		DBObject _id = getAsDBObject(serialized, "_id");
+		Object[] $in = getTypedValue(_id, "$in", Object[].class);
+
+		assertThat($in, Matchers.<Object> arrayContaining(firstId, secondId));
+	}
+
 	class Address {
 		String id;
 		String street;