From 366b5ffd258ed67c40bbd505eaad53fbbd13bb1d Mon Sep 17 00:00:00 2001
From: Mark Paluch <mpaluch@pivotal.io>
Date: Thu, 5 Nov 2020 10:44:53 +0100
Subject: [PATCH] DATAREDIS-1245 - Consider List subtypes used with RedisScript
 as MULTI return type.

We now consider List and subtypes of List to be returned as MULTI return type. Previously, List subtypes were considered to represent the value type.

Original Pull Request: #571
---
 .../data/redis/connection/ReturnType.java     |  7 +++-
 .../redis/connection/ReturnTypeUnitTests.java | 41 +++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 src/test/java/org/springframework/data/redis/connection/ReturnTypeUnitTests.java

diff --git a/src/main/java/org/springframework/data/redis/connection/ReturnType.java b/src/main/java/org/springframework/data/redis/connection/ReturnType.java
index 3709fa3b1..840cdaf54 100644
--- a/src/main/java/org/springframework/data/redis/connection/ReturnType.java
+++ b/src/main/java/org/springframework/data/redis/connection/ReturnType.java
@@ -25,6 +25,7 @@ import org.springframework.lang.Nullable;
  *
  * @author Jennifer Hickey
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 public enum ReturnType {
 
@@ -62,15 +63,19 @@ public enum ReturnType {
 		if (javaType == null) {
 			return ReturnType.STATUS;
 		}
-		if (javaType.isAssignableFrom(List.class)) {
+
+		if (List.class.isAssignableFrom(javaType)) {
 			return ReturnType.MULTI;
 		}
+
 		if (javaType.isAssignableFrom(Boolean.class)) {
 			return ReturnType.BOOLEAN;
 		}
+
 		if (javaType.isAssignableFrom(Long.class)) {
 			return ReturnType.INTEGER;
 		}
+
 		return ReturnType.VALUE;
 	}
 }
diff --git a/src/test/java/org/springframework/data/redis/connection/ReturnTypeUnitTests.java b/src/test/java/org/springframework/data/redis/connection/ReturnTypeUnitTests.java
new file mode 100644
index 000000000..92f52713e
--- /dev/null
+++ b/src/test/java/org/springframework/data/redis/connection/ReturnTypeUnitTests.java
@@ -0,0 +1,41 @@
+/*
+ * 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.redis.connection;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+/**
+ * Unit tests for {@link ReturnType}.
+ *
+ * @author Mark Paluch
+ */
+class ReturnTypeUnitTests {
+
+	@ParameterizedTest // DATAREDIS-1245
+	@ValueSource(classes = { List.class, ArrayList.class, LinkedList.class })
+	void shouldConsiderListsAsMultiType(Class<?> listClass) {
+
+		assertThat(ReturnType.fromJavaType(listClass)).isEqualTo(ReturnType.MULTI);
+	}
+
+}