Fix compiled scripts demo from README

Compiled functions always show up with no metadata, and you can only
guess what the types are from the bean definition. Probably we should
add more information to the bean definition if we have it when we
compile the function.

There is still a problem if user defines functions that are not of
Flux<String> (but that has always been the case).

spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/SingletonTests.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2012-2015 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.web;
+
+import java.net.URI;
+import java.util.function.Supplier;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.context.embedded.LocalServerPort;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.context.annotation.Bean;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.RequestEntity;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import reactor.core.publisher.Flux;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+public class SingletonTests {
+
+	@LocalServerPort
+	private int port;
+	@Autowired
+	private TestRestTemplate rest;
+
+	@Test
+	public void words() throws Exception {
+		ResponseEntity<String> result = rest.exchange(
+				RequestEntity.get(new URI("/words")).build(), String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
+		assertThat(result.getBody()).isEqualTo("[\"foo\",\"bar\"]");
+	}
+
+	@EnableAutoConfiguration
+	@org.springframework.boot.test.context.TestConfiguration
+	protected static class TestConfiguration {
+		@Bean
+		public static BeanDefinitionRegistryPostProcessor processor() {
+			return new BeanDefinitionRegistryPostProcessor() {
+
+				@Override
+				public void postProcessBeanFactory(
+						ConfigurableListableBeanFactory beanFactory)
+						throws BeansException {
+				}
+
+				@Override
+				public void postProcessBeanDefinitionRegistry(
+						BeanDefinitionRegistry registry) throws BeansException {
+					// Simulates what happens whem you add a compiled function
+					RootBeanDefinition beanDefinition = new RootBeanDefinition(MySupplier.class);
+					registry.registerBeanDefinition("words", beanDefinition);
+				}
+			};
+		}
+	}
+	
+	static class MySupplier implements Supplier<Flux<String>> {
+		@Override
+		public Flux<String> get() {
+			return Flux.just("foo", "bar");
+		}
+	}
+}