DATAMONGO-2290 - Polishing.

Extracted complex lambdas into methods.
Added null check.

Original pull request: #762.

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

@@ -15,9 +15,6 @@
  */
 package org.springframework.data.mongodb.core;
 
-import lombok.NonNull;
-import lombok.Value;
-
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -46,8 +43,13 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 import com.mongodb.WriteConcern;
+import com.mongodb.bulk.BulkWriteResult;
+import com.mongodb.client.MongoCollection;
 import com.mongodb.client.model.*;
 
+import lombok.NonNull;
+import lombok.Value;
+
 /**
  * Default implementation for {@link BulkOperations}.
  *
@@ -56,6 +58,7 @@ import com.mongodb.client.model.*;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Minsu Kim
+ * @author Jens Schauder
  * @since 1.9
  */
 class DefaultBulkOperations implements BulkOperations {
@@ -289,32 +292,44 @@ class DefaultBulkOperations implements BulkOperations {
 
 		try {
 
-			com.mongodb.bulk.BulkWriteResult result = mongoOperations.execute(collectionName, collection -> {
-				return collection.bulkWrite(models.stream().map(it -> {
+			com.mongodb.bulk.BulkWriteResult result = mongoOperations.execute(collectionName, this::bulkWriteTo);
 
-					maybeEmitBeforeSaveEvent(it);
+			Assert.state(result != null, "Result must not be null.");
 
-					if (it.getModel() instanceof InsertOneModel) {
+			models.forEach(this::maybeEmitAfterSaveEvent);
 
-						Document target = ((InsertOneModel<Document>) it.getModel()).getDocument();
-						maybeInvokeBeforeSaveCallback(it.getSource(), target);
-					} else if (it.getModel() instanceof ReplaceOneModel) {
-
-						Document target = ((ReplaceOneModel<Document>) it.getModel()).getReplacement();
-						maybeInvokeBeforeSaveCallback(it.getSource(), target);
-					}
-
-					return mapWriteModel(it.getModel());
-				}).collect(Collectors.toList()), bulkOptions);
-			});
-
-			models.stream().forEach(this::maybeEmitAfterSaveEvent);
 			return result;
 		} finally {
 			this.bulkOptions = getBulkWriteOptions(bulkOperationContext.getBulkMode());
 		}
 	}
 
+	private BulkWriteResult bulkWriteTo(MongoCollection<Document> collection) {
+
+		return collection.bulkWrite( //
+				models.stream() //
+						.map(this::extractAndMapWriteModel) //
+						.collect(Collectors.toList()), //
+				bulkOptions);
+	}
+
+	private WriteModel<Document> extractAndMapWriteModel(SourceAwareWriteModelHolder it) {
+
+		maybeEmitBeforeSaveEvent(it);
+
+		if (it.getModel() instanceof InsertOneModel) {
+
+			Document target = ((InsertOneModel<Document>) it.getModel()).getDocument();
+			maybeInvokeBeforeSaveCallback(it.getSource(), target);
+		} else if (it.getModel() instanceof ReplaceOneModel) {
+
+			Document target = ((ReplaceOneModel<Document>) it.getModel()).getReplacement();
+			maybeInvokeBeforeSaveCallback(it.getSource(), target);
+		}
+
+		return mapWriteModel(it.getModel());
+	}
+
 	/**
 	 * Performs update and upsert bulk operations.
 	 *

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

@@ -33,6 +33,7 @@ import org.bson.Document;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Answers;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Captor;
 import org.mockito.Mock;
@@ -78,13 +79,14 @@ import com.mongodb.client.model.WriteModel;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Minsu Kim
+ * @author Jens Schauder
  */
 @RunWith(MockitoJUnitRunner.class)
 public class DefaultBulkOperationsUnitTests {
 
 	MongoTemplate template;
 	@Mock MongoDatabase database;
-	@Mock MongoCollection<Document> collection;
+	@Mock(answer= Answers.RETURNS_DEEP_STUBS) MongoCollection<Document> collection;
 	@Mock MongoDbFactory factory;
 	@Mock DbRefResolver dbRefResolver;
 	@Captor ArgumentCaptor<List<WriteModel<Document>>> captor;
@@ -272,7 +274,7 @@ public class DefaultBulkOperationsUnitTests {
 		verify(eventPublisher).publishEvent(any(AfterSaveEvent.class));
 	}
 
-	@Test
+	@Test // DATAMONGO-2290
 	public void noAfterSaveEventOnFailure() {
 
 		ApplicationEventPublisher eventPublisher = mock(ApplicationEventPublisher.class);

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

@@ -27,6 +27,7 @@ import org.bson.codecs.configuration.CodecRegistry;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Answers;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.springframework.data.geo.Metrics;
@@ -66,6 +67,7 @@ import com.mongodb.client.ClientSession;
  * control the behavior by using the methods dedicated for {@link ClientSession} directly.
  *
  * @author Christoph Strobl
+ * @author Jens Schauder
  */
 @SuppressWarnings("unchecked")
 @RunWith(MockitoJUnitRunner.Silent.class)
@@ -77,7 +79,7 @@ public class SessionBoundMongoTemplateUnitTests {
 
 	MongoDbFactory factory;
 
-	@Mock MongoCollection collection;
+	@Mock(answer = Answers.RETURNS_DEEP_STUBS) MongoCollection collection;
 	@Mock MongoDatabase database;
 	@Mock MongoClient client;
 	@Mock ClientSession clientSession;