Add FunctionType abstraction and test it

2018-02-26 09:56:02 +00:00
parent 42a7babb7d
commit 38f6caf4dc
4 changed files with 350 additions and 14 deletions
--- a/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/FunctionTypeTests.java
+++ b/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/FunctionTypeTests.java
@@ -0,0 +1,163 @@
+/*
+ * 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.lang.reflect.Type;
+import java.util.Collections;
+import java.util.Map;
+import java.util.function.Function;
+
+import org.junit.Test;
+
+import org.springframework.core.ResolvableType;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import reactor.core.publisher.Flux;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class FunctionTypeTests {
+
+	@Test
+	public void plainFunction() {
+		FunctionType function = new FunctionType(IntegerToString.class);
+		assertThat(function.getInputType()).isEqualTo(Integer.class);
+		assertThat(function.getOutputType()).isEqualTo(String.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Integer.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(String.class);
+		assertThat(function.isMessage()).isEqualTo(false);
+	}
+
+	@Test
+	public void genericFunction() {
+		FunctionType function = new FunctionType(StringToMap.class);
+		assertThat(function.getInputType()).isEqualTo(String.class);
+		assertThat(function.getOutputType()).isEqualTo(Map.class);
+		assertThat(function.getInputWrapper()).isEqualTo(String.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(Map.class);
+		assertThat(function.isMessage()).isEqualTo(false);
+	}
+
+	@Test
+	public void pojoFunction() {
+		FunctionType function = new FunctionType(FooToFoo.class);
+		assertThat(function.getInputType()).isEqualTo(Foo.class);
+		assertThat(function.getOutputType()).isEqualTo(Bar.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Foo.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(Bar.class);
+		assertThat(function.isMessage()).isEqualTo(false);
+	}
+
+	@Test
+	public void fluxFunction() {
+		FunctionType function = new FunctionType(FluxToFlux.class);
+		assertThat(function.getInputType()).isEqualTo(Foo.class);
+		assertThat(function.getOutputType()).isEqualTo(Bar.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.isMessage()).isEqualTo(false);
+	}
+
+	@Test
+	public void fluxMessageFunction() {
+		FunctionType function = new FunctionType(FluxMessageToFluxMessage.class);
+		assertThat(function.getInputType()).isEqualTo(Foo.class);
+		assertThat(function.getOutputType()).isEqualTo(Bar.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.isMessage()).isEqualTo(true);
+	}
+
+	@Test
+	public void plainFunctionFromType() {
+		Type type = ResolvableType
+				.forClassWithGenerics(Function.class, Integer.class, String.class)
+				.getType();
+		FunctionType function = new FunctionType(type);
+		assertThat(function.getInputType()).isEqualTo(Integer.class);
+		assertThat(function.getOutputType()).isEqualTo(String.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Integer.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(String.class);
+		assertThat(function.isMessage()).isEqualTo(false);
+	}
+
+	@Test
+	public void fluxMessageFunctionFromType() {
+		Type type = ResolvableType
+				.forClassWithGenerics(Function.class,
+						ResolvableType.forClassWithGenerics(
+								Flux.class,
+								ResolvableType.forClassWithGenerics(Message.class,
+										Foo.class)),
+						ResolvableType.forClassWithGenerics(Flux.class, ResolvableType
+								.forClassWithGenerics(Message.class, Bar.class)))
+				.getType();
+		FunctionType function = new FunctionType(type);
+		assertThat(function.getInputType()).isEqualTo(Foo.class);
+		assertThat(function.getOutputType()).isEqualTo(Bar.class);
+		assertThat(function.getInputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.getOutputWrapper()).isEqualTo(Flux.class);
+		assertThat(function.isMessage()).isEqualTo(true);
+	}
+
+	private static class IntegerToString implements Function<Integer, String> {
+		@Override
+		public String apply(Integer t) {
+			return "" + t;
+		}
+	}
+
+	private static class StringToMap implements Function<String, Map<String, Integer>> {
+		@Override
+		public Map<String, Integer> apply(String t) {
+			return Collections.emptyMap();
+		}
+	}
+
+	private static class FooToFoo implements Function<Foo, Bar> {
+		@Override
+		public Bar apply(Foo t) {
+			return new Bar();
+		}
+	}
+
+	private static class FluxToFlux implements Function<Flux<Foo>, Flux<Bar>> {
+		@Override
+		public Flux<Bar> apply(Flux<Foo> t) {
+			return t.map(f -> new Bar());
+		}
+	}
+
+	private static class FluxMessageToFluxMessage
+			implements Function<Flux<Message<Foo>>, Flux<Message<Bar>>> {
+		@Override
+		public Flux<Message<Bar>> apply(Flux<Message<Foo>> t) {
+			return t.map(f -> MessageBuilder.withPayload(new Bar())
+					.copyHeadersIfAbsent(f.getHeaders()).build());
+		}
+	}
+
+	private static class Foo {
+	}
+
+	private static class Bar {
+	}
+}