Add "wrapper" type methods to FunctionInspector

These can be used to more reliably discover whether the user
has declared a function with flux types or "bare" POJOs. They
then pave the way to supporting single valued types in a special
way.

Also consolidate and simplify the logic in FunctionInspector

spring-cloud-function-samples/spring-cloud-function-sample-pojo/pom.xml

@@ -20,7 +20,7 @@
 	<properties>
 		<java.version>1.8</java.version>
 		<spring-cloud-function.version>1.0.0.BUILD-SNAPSHOT</spring-cloud-function.version>
-		<wrapper.version>1.0.1.RELEASE</wrapper.version>
+		<wrapper.version>1.0.2.RELEASE</wrapper.version>
 		<reactor.version>3.0.7.BUILD-SNAPSHOT</reactor.version>
 	</properties>
 

spring-cloud-function-samples/spring-cloud-function-sample-pojo/src/main/java/com/example/LowercaseConfiguration.java

@@ -0,0 +1,38 @@
+/*
+ * 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 com.example;
+
+import java.util.function.Function;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import reactor.core.publisher.Flux;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@Configuration
+public class LowercaseConfiguration {
+
+	@Bean
+	public Function<Flux<Foo>, Flux<Bar>> lowercase() {
+		return flux -> flux.log().map(value -> new Bar(value.lowercase()));
+	}
+
+}

spring-cloud-function-samples/spring-cloud-function-sample-pojo/src/main/java/com/example/SampleApplication.java

@@ -37,11 +37,6 @@ public class SampleApplication {
 		return () -> Flux.fromArray(new Bar[] { new Bar("foo"), new Bar("bar") }).log();
 	}
 
-	@Bean
-	public Function<Flux<Foo>, Flux<Bar>> lowercase() {
-		return flux -> flux.log().map(value -> new Bar(value.lowercase()));
-	}
-
 	public static void main(String[] args) throws Exception {
 		SpringApplication.run(SampleApplication.class, args);
 	}

spring-cloud-function-samples/spring-cloud-function-sample-pojo/src/test/java/com/example/SampleApplicationTests.java

@@ -52,4 +52,11 @@ public class SampleApplicationTests {
 				String.class)).isEqualTo("[{\"value\":\"FOO\"}]");
 	}
 
+	@Test
+	public void lowercase() {
+		assertThat(new TestRestTemplate().postForObject(
+				"http://localhost:" + port + "/lowercase", "[{\"value\":\"Foo\"}]",
+				String.class)).isEqualTo("[{\"value\":\"foo\"}]");
+	}
+
 }