Add test and fix type inspection for scanned functions

Fixes gh-73

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

@@ -409,8 +409,18 @@ public class ContextFunctionCatalogAutoConfiguration {
 			}
 			else if (source instanceof FileSystemResource) {
 				try {
-					Type type = ClassUtils.forName(definition.getBeanClassName(), null);
-					param = extractType(type, paramType, index);
+					Class<?> beanType = ClassUtils.forName(definition.getBeanClassName(),
+							null);
+					for (Type type : beanType.getGenericInterfaces()) {
+						if (type.getTypeName().startsWith("java.util.function")) {
+							param = extractType(type, paramType, index);
+							break;
+						}
+					}
+					if (param == null) {
+						// Last chance
+						param = beanType;
+					}
 				}
 				catch (ClassNotFoundException e) {
 					throw new IllegalStateException(

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

@@ -32,6 +32,7 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.cloud.function.compiler.CompiledFunctionFactory;
 import org.springframework.cloud.function.compiler.FunctionCompiler;
+import org.springframework.cloud.function.scan.ScannedFunction;
 import org.springframework.cloud.function.test.GenericFunction;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -120,6 +121,15 @@ public class ContextFunctionCatalogAutoConfigurationTests {
 		assertThat(inspector.getInputWrapper("function")).isAssignableFrom(Map.class);
 	}
 
+	@Test
+	public void componentScanBeanFunction() {
+		create(ComponentScanBeanConfiguration.class);
+		assertThat(context.getBean("function")).isInstanceOf(Function.class);
+		assertThat(catalog.lookupFunction("function")).isInstanceOf(Function.class);
+		assertThat(inspector.getInputType("function")).isAssignableFrom(Map.class);
+		assertThat(inspector.getInputWrapper("function")).isAssignableFrom(Map.class);
+	}
+
 	@Test
 	public void componentScanFunction() {
 		create(ComponentScanConfiguration.class);
@@ -285,6 +295,12 @@ public class ContextFunctionCatalogAutoConfigurationTests {
 	@EnableAutoConfiguration
 	@Configuration
 	@ComponentScan(basePackageClasses = GenericFunction.class)
+	protected static class ComponentScanBeanConfiguration {
+	}
+
+	@EnableAutoConfiguration
+	@Configuration
+	@ComponentScan(basePackageClasses = ScannedFunction.class)
 	protected static class ComponentScanConfiguration {
 	}
 

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/scan/ScannedFunction.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2016-2017 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
+ *
+ *      http://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.cloud.function.scan;
+
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@Component("function")
+public class ScannedFunction
+		implements Function<Map<String, String>, Map<String, String>> {
+	@Override
+	public Map<String, String> apply(Map<String, String> m) {
+		return m.entrySet().stream().collect(Collectors.toMap(e -> e.getKey(),
+				e -> e.getValue().toString().toUpperCase()));
+	}
+}