#421 - Polishing.

Simplify tests. Use ReflectionUtils.isVoid(…) where possible and simplify isVoid(…) flows.

Original pull request: #422.

src/main/java/org/springframework/data/r2dbc/repository/query/AbstractR2dbcQuery.java

@@ -144,10 +144,6 @@ public abstract class AbstractR2dbcQuery implements RepositoryQuery {
 				return (q, t, c) -> q.rowsUpdated().then();
 			}
 
-			if (KotlinDetector.isKotlinPresent() && Unit.class.isAssignableFrom(returnedType.getReturnedType())) {
-				return (q, t, c) -> q.rowsUpdated().thenReturn(Unit.INSTANCE);
-			}
-
 			return (q, t, c) -> q.rowsUpdated();
 		}
 

src/main/java/org/springframework/data/r2dbc/repository/query/R2dbcQueryMethod.java

@@ -17,12 +17,9 @@ package org.springframework.data.r2dbc.repository.query;
 
 import static org.springframework.data.repository.util.ClassUtils.*;
 
-import kotlin.Unit;
-
 import java.lang.reflect.Method;
 import java.util.Optional;
 
-import org.springframework.core.KotlinDetector;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.domain.Page;
@@ -45,6 +42,7 @@ import org.springframework.data.repository.util.ReactiveWrapperConverters;
 import org.springframework.data.repository.util.ReactiveWrappers;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.Lazy;
+import org.springframework.data.util.ReflectionUtils;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -169,7 +167,7 @@ public class R2dbcQueryMethod extends QueryMethod {
 			Class<?> domainClass = getDomainClass();
 
 			if (ClassUtils.isPrimitiveOrWrapper(returnedObjectType)
-					|| KotlinDetector.isKotlinPresent() && Unit.class.isAssignableFrom(returnedObjectType)) {
+					|| ReflectionUtils.isVoid(returnedObjectType)) {
 
 				this.metadata = new SimpleRelationalEntityMetadata<>((Class<Object>) domainClass,
 						mappingContext.getRequiredPersistentEntity(domainClass));

src/test/java/org/springframework/data/r2dbc/repository/AbstractR2dbcRepositoryIntegrationTests.java

@@ -17,8 +17,6 @@ package org.springframework.data.r2dbc.repository;
 
 import static org.assertj.core.api.Assertions.*;
 
-import kotlin.Unit;
-
 import io.r2dbc.spi.ConnectionFactory;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
@@ -50,7 +48,7 @@ import org.springframework.data.r2dbc.repository.support.R2dbcRepositoryFactory;
 import org.springframework.data.r2dbc.testing.R2dbcIntegrationTestSupport;
 import org.springframework.data.relational.core.mapping.Table;
 import org.springframework.data.repository.NoRepositoryBean;
-import org.springframework.data.repository.reactive.ReactiveSortingRepository;
+import org.springframework.data.repository.reactive.ReactiveCrudRepository;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.transaction.reactive.TransactionalOperator;
 
@@ -58,7 +56,6 @@ import org.springframework.transaction.reactive.TransactionalOperator;
  * Abstract base class for integration tests for {@link LegoSetRepository} using {@link R2dbcRepositoryFactory}.
  *
  * @author Mark Paluch
- * @author Stephen Cohen
  */
 public abstract class AbstractR2dbcRepositoryIntegrationTests extends R2dbcIntegrationTestSupport {
 
@@ -314,40 +311,6 @@ public abstract class AbstractR2dbcRepositoryIntegrationTests extends R2dbcInteg
 				.verifyComplete();
 	}
 
-	@Test // gh-421
-	public void shouldDeleteAndReturnSuccess() {
-
-		shouldInsertNewItems();
-
-		repository.deleteByManualAndReturnSuccess(12) //
-				.as(StepVerifier::create) //
-				.expectNext(true) //
-				.verifyComplete();
-
-		repository.findAll() //
-				.map(LegoSet::getManual) //
-				.as(StepVerifier::create) //
-				.expectNext(13) //
-				.verifyComplete();
-	}
-
-	@Test // gh-421
-	public void shouldDeleteAndReturnKotlinUnit() {
-
-		shouldInsertNewItems();
-
-		repository.deleteByManualAndReturnKotlinUnit(12) //
-				.as(StepVerifier::create) //
-				.expectNext(Unit.INSTANCE) //
-				.verifyComplete();
-
-		repository.findAll() //
-				.map(LegoSet::getManual) //
-				.as(StepVerifier::create) //
-				.expectNext(13) //
-				.verifyComplete();
-	}
-
 	private Condition<? super Object> numberOf(int expected) {
 		return new Condition<>(it -> {
 			return it instanceof Number && ((Number) it).intValue() == expected;
@@ -355,7 +318,7 @@ public abstract class AbstractR2dbcRepositoryIntegrationTests extends R2dbcInteg
 	}
 
 	@NoRepositoryBean
-	interface LegoSetRepository extends ReactiveSortingRepository<LegoSet, Integer> {
+	interface LegoSetRepository extends ReactiveCrudRepository<LegoSet, Integer> {
 
 		Flux<LegoSet> findByNameContains(String name);
 
@@ -381,14 +344,6 @@ public abstract class AbstractR2dbcRepositoryIntegrationTests extends R2dbcInteg
 		@Query("DELETE from legoset")
 		Mono<Integer> deleteAllAndReturnCount();
 
-		@Modifying
-		@Query("DELETE from legoset where manual = :manual")
-		Mono<Boolean> deleteByManualAndReturnSuccess(int manual);
-
-		@Modifying
-		@Query("DELETE from legoset where manual = :manual")
-		Mono<Unit> deleteByManualAndReturnKotlinUnit(int manual);
-
 		Mono<Integer> countByNameContains(String namePart);
 	}