Add basic test for reactive caching

spring-context/src/test/java/org/springframework/cache/annotation/ReactiveCachingTests.java

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+/*
+ * Copyright 2002-2023 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.cache.annotation;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.concurrent.ConcurrentMapCacheManager;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for annotation-based caching methods that use reactive operators.
+ *
+ * @author Stephane Nicoll
+ */
+public class ReactiveCachingTests {
+
+	private final ConfigurableApplicationContext ctx;
+
+	private final ReactiveCacheableService service;
+
+	public ReactiveCachingTests() {
+		this.ctx = new AnnotationConfigApplicationContext(TestConfig.class);
+		this.service = this.ctx.getBean(ReactiveCacheableService.class);
+	}
+
+	@Test
+	void cache() {
+		Object key = new Object();
+		Long r1 = this.service.cache(key).block();
+		Long r2 = this.service.cache(key).block();
+		Long r3 = this.service.cache(key).block();
+		assertThat(r1).isSameAs(r2).isSameAs(r3);
+	}
+
+
+	@CacheConfig(cacheNames = "first")
+	static class ReactiveCacheableService {
+
+		private final AtomicLong counter = new AtomicLong();
+
+		@Cacheable
+		Mono<Long> cache(Object arg1) {
+			return Mono.just(this.counter.getAndIncrement());
+		}
+
+	}
+
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableCaching
+	static class TestConfig {
+
+		@Bean
+		CacheManager cacheManager() {
+			return new ConcurrentMapCacheManager("first");
+		}
+
+		@Bean
+		ReactiveCacheableService reactiveCacheableService() {
+			return new ReactiveCacheableService();
+		}
+
+	}
+
+}