hacking - apply value conversion at query creation time for regex.

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

@@ -1571,6 +1571,39 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		return newDocument;
 	}
 
+	@Nullable
+	@Override
+	public Object convertToMongoType(@Nullable Object obj, MongoPersistentProperty property) {
+
+		PersistentPropertyAccessor accessor = new MapPersistentPropertyAccessor();
+		accessor.setProperty(property, obj);
+
+		Document newDocument = new Document();
+		DocumentAccessor dbObjectAccessor = new DocumentAccessor(newDocument);
+
+		if (property.isIdProperty() || !property.isWritable()) {
+			return obj;
+		}
+		if (property.isAssociation()) {
+
+			writeAssociation(property.getRequiredAssociation(), accessor, dbObjectAccessor);
+			return dbObjectAccessor.get(property);
+		}
+
+		Object value = obj;
+
+		if (value == null) {
+			if (property.writeNullValues()) {
+				dbObjectAccessor.put(property, null);
+			}
+		} else if (!conversions.isSimpleType(value.getClass())) {
+			writePropertyInternal(value, dbObjectAccessor, property, accessor);
+		} else {
+			writeSimpleInternal(value, newDocument, property, accessor);
+		}
+		return dbObjectAccessor.get(property);
+	}
+
 	// TODO: hide in 4.0
 	public List<Object> maybeConvertList(Iterable<?> source, @Nullable TypeInformation<?> typeInformation) {
 

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

@@ -42,12 +42,15 @@ import org.springframework.data.convert.PropertyValueConverter;
 import org.springframework.data.convert.PropertyValueConverterFactory;
 import org.springframework.data.convert.PropertyValueConverterRegistrar;
 import org.springframework.data.convert.SimplePropertyValueConversions;
+import org.springframework.data.convert.ValueConversionContext;
 import org.springframework.data.convert.WritingConverter;
+import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.mongodb.core.mapping.MongoSimpleTypes;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Value object to capture custom conversion. {@link MongoCustomConversions} also act as factory for
@@ -331,9 +334,40 @@ public class MongoCustomConversions extends org.springframework.data.convert.Cus
 				svc.init();
 			}
 
+			// Move to data-commons?
+			PropertyValueConversions pvc = new PropertyValueConversions() {
+
+				@Override
+				public boolean hasValueConverter(PersistentProperty<?> property) {
+					return propertyValueConversions.hasValueConverter(property);
+				}
+
+				@Override
+				public <DV, SV, P extends PersistentProperty<P>, VCC extends ValueConversionContext<P>> PropertyValueConverter<DV, SV, VCC> getValueConverter(
+						P property) {
+
+					return new PropertyValueConverter<DV, SV, VCC>() {
+
+						@Nullable
+						@Override
+						public DV read(SV value, VCC context) {
+							return (DV) propertyValueConversions.getValueConverter(property).read(value, context);
+						}
+
+						@Nullable
+						@Override
+						public SV write(DV value, VCC context) {
+							if (ClassUtils.isAssignable(property.getType(), value.getClass())) {
+								return (SV) propertyValueConversions.getValueConverter(property).write(value, context);
+							}
+							return (SV) value;
+						}
+					};
+				}
+			};
+
 			if (!useNativeDriverJavaTimeCodecs) {
-				return new ConverterConfiguration(STORE_CONVERSIONS, this.customConverters, convertiblePair -> true,
+				return new ConverterConfiguration(STORE_CONVERSIONS, this.customConverters, convertiblePair -> true, pvc);
-						this.propertyValueConversions);
 			}
 
 			/*
@@ -358,7 +392,7 @@ public class MongoCustomConversions extends org.springframework.data.convert.Cus
 				}
 
 				return true;
-			}, this.propertyValueConversions);
+			}, pvc);
 		}
 
 		private enum DateToUtcLocalDateTimeConverter implements Converter<Date, LocalDateTime> {

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

@@ -59,6 +59,11 @@ public interface MongoWriter<T> extends EntityWriter<T, Bson> {
 	@Nullable
 	Object convertToMongoType(@Nullable Object obj, @Nullable TypeInformation<?> typeInformation);
 
+	@Nullable
+	default Object convertToMongoType(@Nullable Object obj, MongoPersistentProperty property) {
+		return convertToMongoType(obj, property.getTypeInformation());
+	}
+
 	default Object convertToMongoType(@Nullable Object obj, MongoPersistentEntity<?> entity) {
 		return convertToMongoType(obj, entity.getTypeInformation());
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/ConvertingParameterAccessor.java

@@ -36,9 +36,11 @@ import org.springframework.data.repository.query.ParameterAccessor;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 
 import com.mongodb.DBRef;
+import org.springframework.util.ObjectUtils;
 
 /**
  * Custom {@link ParameterAccessor} that uses a {@link MongoWriter} to serialize parameters into Mongo format.
@@ -91,7 +93,7 @@ public class ConvertingParameterAccessor implements MongoParameterAccessor {
 	}
 
 	public Object getBindableValue(int index) {
-		return getConvertedValue(delegate.getBindableValue(index), null);
+		return getConvertedValue(delegate.getBindableValue(index), (TypeInformation<?>) null);
 	}
 
 	@Override
@@ -129,6 +131,11 @@ public class ConvertingParameterAccessor implements MongoParameterAccessor {
 		return writer.convertToMongoType(value, typeInformation == null ? null : typeInformation.getActualType());
 	}
 
+
+	public Object getConvertedValue(Object value, MongoPersistentProperty property) {
+		return writer.convertToMongoType(value, property);
+	}
+
 	public boolean hasBindableNullValue() {
 		return delegate.hasBindableNullValue();
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/MongoQueryCreator.java

@@ -68,7 +68,7 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 
 	private static final Log LOG = LogFactory.getLog(MongoQueryCreator.class);
 
-	private final MongoParameterAccessor accessor;
+	private final ConvertingParameterAccessor accessor;
 	private final MappingContext<?, MongoPersistentProperty> context;
 	private final boolean isGeoNearQuery;
 
@@ -345,6 +345,17 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
 					"Argument for creating $regex pattern for property '%s' must not be null", part.getProperty().getSegment()));
 		}
 
+		try {
+			PersistentPropertyPath<MongoPersistentProperty> persistentPropertyPath = context.getPersistentPropertyPath(part.getProperty());
+			MongoPersistentProperty leafProperty = persistentPropertyPath.getLeafProperty();/// maybe a call back here
+			if (leafProperty != null) {
+				Object convertedValue = accessor.getConvertedValue(value.toString(), leafProperty);
+				return criteria.regex(toLikeRegex(convertedValue.toString(), part), toRegexOptions(part));
+			}
+		} catch (Exception ex) {
+			System.err.print(ex);
+		}
+
 		return criteria.regex(toLikeRegex(value.toString(), part), toRegexOptions(part));
 	}
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/ReversingValueConverter.java

@@ -13,14 +13,16 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.data.mongodb.core.convert;
+package org.springframework.data.mongodb;
 
+import org.springframework.data.mongodb.core.convert.MongoConversionContext;
+import org.springframework.data.mongodb.core.convert.MongoValueConverter;
 import org.springframework.lang.Nullable;
 
 /**
  * @author Christoph Strobl
  */
-class ReversingValueConverter implements MongoValueConverter<String, String> {
+public class ReversingValueConverter implements MongoValueConverter<String, String> {
 
 	@Nullable
 	@Override

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

@@ -29,6 +29,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
+import org.bson.BsonRegularExpression;
 import org.bson.conversions.Bson;
 import org.bson.types.Code;
 import org.bson.types.ObjectId;
@@ -42,6 +43,7 @@ import org.springframework.data.convert.WritingConverter;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.geo.Point;
+import org.springframework.data.mongodb.ReversingValueConverter;
 import org.springframework.data.mongodb.core.DocumentTestUtils;
 import org.springframework.data.mongodb.core.Person;
 import org.springframework.data.mongodb.core.aggregation.ComparisonOperators;
@@ -1455,6 +1457,15 @@ public class QueryMapperUnitTests {
 		assertThat(mappedObject).isEqualTo(new org.bson.Document("text", "eulav"));
 	}
 
+	@Test // GH-4346
+	void ignoresValueConverterForNonMatchingType() {
+
+		org.bson.Document source = new org.bson.Document("text", new BsonRegularExpression("value"));
+		org.bson.Document mappedObject = mapper.getMappedObject(source, context.getPersistentEntity(WithPropertyValueConverter.class));
+
+		assertThat(mappedObject).isEqualTo(source);
+	}
+
 	@Test // GH-2750
 	void mapsAggregationExpression() {
 

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

@@ -47,9 +47,8 @@ import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.domain.Sort.Order;
 import org.springframework.data.mapping.MappingException;
+import org.springframework.data.mongodb.ReversingValueConverter;
 import org.springframework.data.mongodb.core.DocumentTestUtils;
-import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
-import org.springframework.data.mongodb.core.convert.UpdateMapper;
 import org.springframework.data.mongodb.core.mapping.DocumentReference;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;

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

@@ -1637,4 +1637,19 @@ public abstract class AbstractPersonRepositoryIntegrationTests implements Dirtie
 		assertThat(repository.findById(dave.getId()).map(Person::getShippingAddresses))
 				.contains(Collections.singleton(address));
 	}
+
+	@Test // GH-4346
+	@DirtiesState
+	void findCreatingRegexWithValueConverterWorks() {
+
+		Person bart = new Person("bart", "simpson");
+		bart.setNickName("bartman");
+
+		operations.save(bart);
+
+		List<Person> result = repository.findByNickNameContains("artma");
+
+		assertThat(result).hasSize(1);
+		assertThat(result.get(0).getId().equals(bart.getId()));
+	}
 }

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

@@ -21,7 +21,9 @@ import java.util.List;
 import java.util.Set;
 import java.util.UUID;
 
+import org.springframework.data.convert.ValueConverter;
 import org.springframework.data.geo.Point;
+import org.springframework.data.mongodb.ReversingValueConverter;
 import org.springframework.data.mongodb.core.index.GeoSpatialIndexType;
 import org.springframework.data.mongodb.core.index.GeoSpatialIndexed;
 import org.springframework.data.mongodb.core.index.Indexed;
@@ -78,6 +80,9 @@ public class Person extends Contact {
 
 	@DocumentReference User spiritAnimal;
 
+	@ValueConverter(ReversingValueConverter.class)
+	String nickName;
+
 	int visits;
 
 	public Person() {
@@ -325,6 +330,14 @@ public class Person extends Contact {
 		this.spiritAnimal = spiritAnimal;
 	}
 
+	public String getNickName() {
+		return nickName;
+	}
+
+	public void setNickName(String nickName) {
+		this.nickName = nickName;
+	}
+
 	@Override
 	public int hashCode() {
 

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

@@ -465,4 +465,5 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 
 	List<Person> findBySpiritAnimal(User user);
 
+	List<Person> findByNickNameContains(String nickName);
 }

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

@@ -29,6 +29,7 @@ import org.bson.Document;
 import org.bson.types.ObjectId;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.data.convert.ValueConverter;
 import org.springframework.data.domain.Range;
 import org.springframework.data.domain.Range.Bound;
 import org.springframework.data.geo.Distance;
@@ -40,7 +41,9 @@ import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.Person;
 import org.springframework.data.mongodb.core.Venue;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
+import org.springframework.data.mongodb.core.convert.MongoConversionContext;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.convert.MongoValueConverter;
 import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
 import org.springframework.data.mongodb.core.geo.GeoJsonLineString;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
@@ -57,6 +60,7 @@ import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.Repository;
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
 import org.springframework.data.repository.query.parser.PartTree;
+import org.springframework.lang.Nullable;
 
 /**
  * Unit test for {@link MongoQueryCreator}.
@@ -658,6 +662,16 @@ class MongoQueryCreatorUnitTests {
 		assertThat(creator.createQuery()).isEqualTo(query(where("location").nearSphere(point).maxDistance(1000.0D)));
 	}
 
+	@Test // GH-4346
+	void likeQueriesShouldApplyPropertyValueConverterWhenCreatingRegex() {
+
+		PartTree tree = new PartTree("findByTextStartingWith", WithValueConverter.class);
+		MongoQueryCreator creator = new MongoQueryCreator(tree, getAccessor(converter, "spring"), context);
+		Query query = creator.createQuery();
+
+		assertThat(query).isEqualTo(query(where("text").regex("^gnirps")));
+	}
+
 	interface PersonRepository extends Repository<Person, Long> {
 
 		List<Person> findByLocationNearAndFirstname(Point location, Distance maxDistance, String firstname);
@@ -693,4 +707,34 @@ class MongoQueryCreatorUnitTests {
 
 		@GeoSpatialIndexed(type = GeoSpatialIndexType.GEO_2DSPHERE) Point geo;
 	}
+
+	static class WithValueConverter {
+
+		@ValueConverter(ReversingValueConverter.class)
+		String text;
+	}
+
+	static class ReversingValueConverter implements MongoValueConverter<String, String> {
+
+		@Nullable
+		@Override
+		public String read(@Nullable String value, MongoConversionContext context) {
+			return reverse(value);
+		}
+
+		@Nullable
+		@Override
+		public String write(@Nullable String value, MongoConversionContext context) {
+			return reverse(value);
+		}
+
+		private String reverse(String source) {
+
+			if (source == null) {
+				return null;
+			}
+
+			return new StringBuilder(source).reverse().toString();
+		}
+	}
 }

spring-data-mongodb/src/test/resources/logback.xml

@@ -9,6 +9,10 @@
 
 	<appender name="no-op" class="ch.qos.logback.core.helpers.NOPAppender" />
 
+	<!--
+	<logger name="org.mongodb.driver.protocol" level="DEBUG" />
+	-->
+
 	<!--
 	<logger name="org.springframework" level="debug" />
 	 -->