Support for Function<Publisher<...>,...>

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/FunctionInspector.java

@@ -19,6 +19,8 @@ package org.springframework.cloud.function.context.catalog;
 import java.lang.reflect.Type;
 import java.util.Optional;
 
+import org.reactivestreams.Publisher;
+
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -44,7 +46,7 @@ public interface FunctionInspector {
 
 	// Maybe make this a default method?
 	static boolean isWrapper(Type type) {
-		return Flux.class.equals(type) || Mono.class.equals(type)
+		return Publisher.class.equals(type) || Flux.class.equals(type) || Mono.class.equals(type)
 				|| Optional.class.equals(type);
 	}
 

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/config/ContextFunctionCatalogAutoConfigurationTests.java

@@ -16,8 +16,6 @@
 
 package org.springframework.cloud.function.context.config;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
@@ -30,6 +28,7 @@ import java.util.stream.Collectors;
 
 import org.junit.After;
 import org.junit.Test;
+import org.reactivestreams.Publisher;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -63,6 +62,8 @@ import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StreamUtils;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 import reactor.core.publisher.Flux;
 
 /**
@@ -175,6 +176,18 @@ public class ContextFunctionCatalogAutoConfigurationTests {
 				.isAssignableFrom(Flux.class);
 	}
 
+	@Test
+	public void publisherMessageFunction() {
+		create(PublisherMessageConfiguration.class);
+		assertThat(context.getBean("function")).isInstanceOf(Function.class);
+		assertThat(catalog.lookupFunction("function")).isInstanceOf(Function.class);
+		assertThat(inspector.isMessage(catalog.lookupFunction("function"))).isTrue();
+		assertThat(inspector.getInputType(catalog.lookupFunction("function")))
+				.isAssignableFrom(String.class);
+		assertThat(inspector.getInputWrapper(catalog.lookupFunction("function")))
+				.isAssignableFrom(Publisher.class);
+	}
+
 	@Test
 	public void messageFunction() {
 		create(MessageConfiguration.class);
@@ -572,6 +585,16 @@ public class ContextFunctionCatalogAutoConfigurationTests {
 		}
 	}
 
+	@EnableAutoConfiguration
+	@Configuration
+	protected static class PublisherMessageConfiguration {
+		@Bean
+		public Function<Publisher<Message<String>>, Publisher<Message<String>>> function() {
+			return flux -> Flux.from(flux).map(m -> MessageBuilder
+					.withPayload(m.getPayload().toUpperCase()).build());
+		}
+	}
+
 	@EnableAutoConfiguration
 	@Configuration
 	protected static class MessageConfiguration {