Support enum arguments on repository queries.

src/main/java/org/springframework/data/couchbase/core/convert/AbstractCouchbaseConverter.java

@@ -17,6 +17,7 @@
 package org.springframework.data.couchbase.core.convert;
 
 import java.util.Collections;
+import java.util.Optional;
 
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.convert.ConversionService;
@@ -100,7 +101,8 @@ public Object convertForWriteIfNeeded(Object value) {
 
 		return this.conversions.getCustomWriteTarget(value.getClass()) //
 				.map(it -> (Object) this.conversionService.convert(value, it)) //
-				.orElse(value);
+				.orElseGet(() -> Enum.class.isAssignableFrom(value.getClass()) ? ((Enum<?>) value).name() : value);
+
 	}
 
 	@Override

src/main/java/org/springframework/data/couchbase/core/convert/MappingCouchbaseConverter.java

@@ -774,15 +774,8 @@ private void writeSimpleInternal(final Object source, final CouchbaseDocument ta
 		target.put(key, getPotentiallyConvertedSimpleWrite(source));
 	}
 
-	private Object getPotentiallyConvertedSimpleWrite(final Object value) {
-		if (value == null) {
-			return null;
-		}
-
-		Optional<Class<?>> customTarget = conversions.getCustomWriteTarget(value.getClass());
-
-		return customTarget.map(it -> (Object) conversionService.convert(value, it))
-				.orElseGet(() -> Enum.class.isAssignableFrom(value.getClass()) ? ((Enum<?>) value).name() : value);
+	public Object getPotentiallyConvertedSimpleWrite(final Object value) {
+		return convertForWriteIfNeeded(value);
 	}
 
 	/**

src/test/java/org/springframework/data/couchbase/domain/AirportRepository.java

@@ -50,6 +50,9 @@ public interface AirportRepository extends PagingAndSortingRepository<Airport, S
 	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
 	Airport findByIata(String iata);
 
+	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
+	Airport findByIata(Iata iata);
+
 	@Query("#{#n1ql.selectEntity} where iata = $1")
 	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
 	List<Airport> getAllByIata(String iata);

src/test/java/org/springframework/data/couchbase/domain/Iata.java

@@ -0,0 +1,6 @@
+package org.springframework.data.couchbase.domain;
+
+public enum Iata {
+  vie,
+  xxx
+}

src/test/java/org/springframework/data/couchbase/repository/CouchbaseRepositoryQueryIntegrationTests.java

@@ -47,6 +47,7 @@
 import org.springframework.data.couchbase.domain.Address;
 import org.springframework.data.couchbase.domain.Airport;
 import org.springframework.data.couchbase.domain.AirportRepository;
+import org.springframework.data.couchbase.domain.Iata;
 import org.springframework.data.couchbase.domain.Person;
 import org.springframework.data.couchbase.domain.PersonRepository;
 import org.springframework.data.couchbase.domain.User;
@@ -167,6 +168,18 @@ void findBySimpleProperty() {
 		}
 	}
 
+	@Test
+	void findByEnum() {
+		Airport vie = null;
+		try {
+			vie = new Airport("airports::vie", "vie", "loww");
+			vie = airportRepository.save(vie);
+			Airport airport2 = airportRepository.findByIata(Iata.vie);
+			assertEquals(airport2.getId(), vie.getId());
+		} finally {
+			airportRepository.delete(vie);
+		}
+	}
 	@Test
 	public void testCas() {
 		User user = new User("1", "Dave", "Wilson");