DATAJDBC-539 - Fix parameter wrapping for IN criteria.

We now no longer double-wrap parameters for IN criteria. Previously, collection arguments were wrapped into another collection which caused double-wrapped lists.

Original pull request: #217.

spring-data-relational/src/main/java/org/springframework/data/relational/repository/query/CriteriaFactory.java

@@ -15,10 +15,14 @@
  */
 package org.springframework.data.relational.repository.query;
 
+import java.util.Collection;
+import java.util.Collections;
+
 import org.springframework.data.relational.core.query.Criteria;
 import org.springframework.data.relational.core.sql.Expression;
 import org.springframework.data.repository.query.parser.Part;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Simple factory to contain logic to create {@link Criteria}s from {@link Part}s.
@@ -90,8 +94,8 @@ class CriteriaFactory {
 			case IN:
 			case NOT_IN: {
 				ParameterMetadata paramMetadata = parameterMetadataProvider.next(part);
-				Criteria criteria = part.getType() == Part.Type.IN ? criteriaStep.in(paramMetadata.getValue())
-						: criteriaStep.notIn(paramMetadata.getValue());
+				Criteria criteria = part.getType() == Part.Type.IN ? criteriaStep.in(asCollection(paramMetadata.getValue()))
+						: criteriaStep.notIn(asCollection(paramMetadata.getValue()));
 				return criteria.ignoreCase(shouldIgnoreCase(part) && checkCanUpperCase(part, part.getProperty().getType()));
 			}
 			case STARTING_WITH:
@@ -163,4 +167,18 @@ class CriteriaFactory {
 	private boolean canUpperCase(Class<?> expressionType) {
 		return expressionType == String.class;
 	}
+
+	@SuppressWarnings("unchecked")
+	private static Collection<Object> asCollection(Object value) {
+
+		if (value instanceof Collection) {
+			return (Collection<Object>) value;
+		}
+
+		if (value.getClass().isArray()) {
+			return CollectionUtils.arrayToList(value);
+		}
+
+		return Collections.singletonList(value);
+	}
 }

spring-data-relational/src/test/java/org/springframework/data/relational/repository/query/CriteriaFactoryUnitTests.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2020 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.relational.repository.query;
+
+import static org.assertj.core.api.Assertions.*;
+
+import lombok.Data;
+import lombok.SneakyThrows;
+
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
+import org.springframework.data.relational.core.query.Criteria;
+import org.springframework.data.repository.Repository;
+import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
+import org.springframework.data.repository.query.QueryMethod;
+import org.springframework.data.repository.query.parser.Part;
+
+/**
+ * Unit tests for {@link CriteriaFactory}.
+ * 
+ * @author Mark Paluch
+ */
+public class CriteriaFactoryUnitTests {
+
+	@Test // DATAJDBC-539
+	void shouldConsiderIterableValuesInInOperator() {
+
+		QueryMethod queryMethod = getQueryMethod("findAllByNameIn", List.class);
+		RelationalParametersParameterAccessor accessor = getAccessor(queryMethod, Arrays.asList("foo", "bar"));
+		ParameterMetadataProvider parameterMetadata = new ParameterMetadataProvider(accessor);
+		CriteriaFactory criteriaFactory = new CriteriaFactory(parameterMetadata);
+
+		Part part = new Part("NameIn", User.class);
+
+		Criteria criteria = criteriaFactory.createCriteria(part);
+
+		assertThat(criteria.getValue()).isEqualTo(Arrays.asList("foo", "bar"));
+	}
+
+	@Test // DATAJDBC-539
+	void shouldConsiderArrayValuesInInOperator() {
+
+		QueryMethod queryMethod = getQueryMethod("findAllByNameIn", String[].class);
+
+		RelationalParametersParameterAccessor accessor = getAccessor(queryMethod,
+				new Object[] { new String[] { "foo", "bar" } });
+		ParameterMetadataProvider parameterMetadata = new ParameterMetadataProvider(accessor);
+		CriteriaFactory criteriaFactory = new CriteriaFactory(parameterMetadata);
+
+		Part part = new Part("NameIn", User.class);
+
+		Criteria criteria = criteriaFactory.createCriteria(part);
+
+		assertThat(criteria.getValue()).isEqualTo(Arrays.asList("foo", "bar"));
+	}
+
+	@SneakyThrows
+	private QueryMethod getQueryMethod(String methodName, Class<?>... parameterTypes) {
+		Method method = UserRepository.class.getMethod(methodName, parameterTypes);
+		return new QueryMethod(method, new DefaultRepositoryMetadata(UserRepository.class),
+				new SpelAwareProxyProjectionFactory());
+	}
+
+	private RelationalParametersParameterAccessor getAccessor(QueryMethod queryMethod, Object... values) {
+		return new RelationalParametersParameterAccessor(queryMethod, values);
+	}
+
+	interface UserRepository extends Repository<User, Long> {
+
+		User findAllByNameIn(List<String> names);
+
+		User findAllByNameIn(String[] names);
+	}
+
+	@Data
+	static class User {
+
+		String name;
+	}
+}