Add composite function support for the sources

function/filter-function/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  org.springframework.cloud.fn.filter.FilterFunctionConfiguration

function/header-enricher-function/src/main/java/org/springframework/cloud/fn/header/enricher/HeaderEnricherFunctionConfiguration.java

@@ -24,6 +24,7 @@ import java.util.function.Function;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -39,6 +40,7 @@ import org.springframework.messaging.Message;
  */
 @Configuration
 @EnableConfigurationProperties(HeaderEnricherFunctionProperties.class)
+@ConditionalOnProperty(prefix = "header.enricher", value = "headers")
 public class HeaderEnricherFunctionConfiguration {
 
 	@Autowired

function/header-enricher-function/src/main/java/org/springframework/cloud/fn/header/enricher/HeaderEnricherFunctionProperties.java

@@ -16,7 +16,6 @@
 
 package org.springframework.cloud.fn.header.enricher;
 
-
 import java.util.Properties;
 
 import javax.validation.constraints.NotNull;
@@ -36,13 +35,13 @@ import org.springframework.validation.annotation.Validated;
 public class HeaderEnricherFunctionProperties {
 
 	/**
-	 * \n separated properties representing headers in which values are SpEL expressions,
-	 * e.g foo='bar' \n baz=payload.baz.
+	 * \n separated properties representing headers in which values are SpEL expressions, e.g
+	 * foo='bar' \n baz=payload.baz.
 	 */
 	private Properties headers;
 
 	/**
-	 *  set to true to overwrite any existing message headers.
+	 * set to true to overwrite any existing message headers.
 	 */
 	private boolean overwrite = false;
 

function/header-enricher-function/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  org.springframework.cloud.fn.header.enricher.HeaderEnricherFunctionConfiguration

function/payload-converter-function/src/main/java/functions/ToMessage.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2020-2020 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 functions;
+
+import java.util.function.Function;
+
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+
+/**
+ * Wrap a POJO as a message.
+ *
+ */
+// TODO: Remove when https://github.com/spring-cloud/spring-cloud-function/issues/550 is
+// resolved.
+public class ToMessage implements Function<Object, Message<?>> {
+	@Override
+	public Message<?> apply(Object o) {
+		return MessageBuilder.withPayload(o).build();
+	}
+}

function/spel-function/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  org.springframework.cloud.fn.spel.SpelFunctionConfiguration

function/splitter-function/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  org.springframework.cloud.fn.splitter.SplitterFunctionConfiguration

function/task-launch-request-function/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  org.springframework.cloud.fn.task.launch.request.TaskLaunchRequestFunctionConfiguration