Re-order type discovery and function wrapping

Otherwise the explicit types from the function registration are
not used.

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

@@ -0,0 +1,45 @@
+/*
+ * 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.context;
+
+import java.util.function.Function;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class FunctionRegistrationTests {
+
+	@Test
+	public void noTypeByDefault() {
+		FunctionRegistration<?> registration = new FunctionRegistration<>(new Foos())
+				.names("foos");
+		assertThat(registration.getType()).isNull();
+		assertThat(registration.getNames()).contains("foos");
+	}
+
+	private static class Foos implements Function<Integer, String> {
+		@Override
+		public String apply(Integer t) {
+			return "i=" + t;
+		}
+	}
+
+}

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

@@ -25,6 +25,7 @@ import java.util.function.Supplier;
 import org.junit.Test;
 
 import org.springframework.cloud.function.context.FunctionRegistration;
+import org.springframework.cloud.function.context.FunctionType;
 import org.springframework.cloud.function.context.config.ContextFunctionCatalogAutoConfiguration.BeanFactoryFunctionCatalog;
 import org.springframework.cloud.function.context.config.ContextFunctionCatalogAutoConfiguration.ContextFunctionRegistry;
 
@@ -55,6 +56,26 @@ public class BeanFactoryFunctionCatalogTests {
 		assertThat(foos.apply(Flux.just(2)).blockFirst()).isEqualTo("4");
 	}
 
+	@Test
+	public void registerFunctionWithType() {
+		processor.register(new FunctionRegistration<Function<Integer, String>>(
+				(Integer i) -> "i=" + i).names("foos").type(
+						FunctionType.from(Integer.class).to(String.class).getType()));
+		Function<Flux<Integer>, Flux<String>> foos = processor.lookupFunction("");
+		assertThat(foos.apply(Flux.just(2)).blockFirst()).isEqualTo("i=2");
+	}
+
+	@Test
+	public void registerFunctionWithFluxType() {
+		processor
+				.register(new FunctionRegistration<Function<Flux<Integer>, Flux<String>>>(
+						ints -> ints.map(i -> "i=" + i)).names("foos")
+								.type(FunctionType.from(Integer.class).to(String.class)
+										.wrap(Flux.class).getType()));
+		Function<Flux<Integer>, Flux<String>> foos = processor.lookupFunction("");
+		assertThat(foos.apply(Flux.just(2)).blockFirst()).isEqualTo("i=2");
+	}
+
 	@Test
 	public void lookupNonExistentConsumerWithEmptyName() {
 		processor.register(new FunctionRegistration<>(new Foos()).names("foos"));