Improve support for disabling TestSupportBinderAutoConfiguration

Fixes #573

- Split TestSupportBinderAutoConfiguration into separate configs
  for the binder, binderfactory and message collector.
  This enables to address the testBinder as a regular binder when
  autoconfiguration is disabled, and to ensure that the message
  collector is available when the autoconfiguration is disabled.
- reorganize tests to use the default autoconfiguration options
- add documentation for disabling test binder autoconfiguration

spring-cloud-stream-core-docs/src/main/asciidoc/spring-cloud-stream-overview.adoc

@@ -1997,6 +1997,31 @@ The bound interface is injected into the test so we can have access to both chan
 We are sending a message on the input channel and we are using the `MessageCollector` provided by Spring Cloud Stream's test support to capture the message has been sent to the output channel as a result.
 Once we have received the message, we can validate that the component functions correctly.
 
+=== Disabling the test binder autoconfiguration
+
+The intent behind the test binder superseding all the other binders on the classpath is to make it easy to test your applications without making changes to your production dependencies.
+In some cases (e.g. integration tests) it is useful to use the actual production binders instead, and that requires disabling the test binder autoconfiguration.
+In order to do so, you can exclude the `org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration` class using one of the Spring Boot autoconfiguration exclusion mechanisms, as in the following example.
+
+[source,java]
+----
+	@SpringBootApplication(exclude = TestSupportBinderAutoConfiguration.class)
+	@EnableBinding(Processor.class)
+	public static class MyProcessor {
+
+		@Transformer(inputChannel = Processor.INPUT, outputChannel = Processor.OUTPUT)
+		public String transform(String in) {
+			return in + " world";
+		}
+	}
+----
+
+When autoconfiguration is disabled, the test binder is available on the classpath, and its `defaultCandidate` property is set to `false`, so that it does not interfere with the regular user configuration. It can be referenced under the name `test` e.g.:
+
+----
+spring.cloud.stream.defaultBinder=test
+----
+
 == Health Indicator
 
 Spring Cloud Stream provides a health indicator for binders.

spring-cloud-stream-test-support/src/main/java/org/springframework/cloud/stream/test/binder/MessageCollectorAutoConfiguration.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 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.stream.test.binder;
+
+import org.springframework.cloud.stream.binder.BinderFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.MessageChannel;
+
+/**
+ * Automatically registers the {@link MessageCollector} associated with the test binder as
+ * a bean.
+ *
+ * @author Marius Bogoevici
+ */
+@Configuration
+public class MessageCollectorAutoConfiguration {
+
+	@Bean
+	public MessageCollector messageCollector(BinderFactory binderFactory) {
+		return ((TestSupportBinder) binderFactory.getBinder("test", MessageChannel.class)).messageCollector();
+	}
+
+}

spring-cloud-stream-test-support/src/main/java/org/springframework/cloud/stream/test/binder/TestSupportBinderAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 the original author or authors.
+ * Copyright 2015-2017 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.
@@ -23,6 +23,7 @@ import org.springframework.cloud.stream.binder.ConsumerProperties;
 import org.springframework.cloud.stream.binder.ProducerProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 import org.springframework.core.Ordered;
 import org.springframework.messaging.MessageChannel;
 
@@ -34,29 +35,24 @@ import org.springframework.messaging.MessageChannel;
  * configuration, so adding this on the classpath in test scope is sufficient to have
  * support kick in and replace all binders with the test binder.
  *
+ * The test binder instance is supplied by the {@link TestSupportBinderConfiguration}.
+ *
  * @author Eric Bottard
  * @author Marius Bogoevici
  */
 @Configuration
 @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
+@Import(TestSupportBinderConfiguration.class)
 public class TestSupportBinderAutoConfiguration {
 
-	private Binder<MessageChannel, ?, ?> messageChannelBinder = new TestSupportBinder();
-
 	@Bean
-	public BinderFactory binderFactory() {
+	public BinderFactory binderFactory(final Binder<MessageChannel, ?, ?> binder) {
 		return new BinderFactory() {
 			@Override
 			public <T> Binder<T, ? extends ConsumerProperties, ? extends ProducerProperties> getBinder(
 					String configurationName, Class<? extends T> bindableType) {
-				return (Binder<T, ? extends ConsumerProperties, ? extends ProducerProperties>) messageChannelBinder;
+				return (Binder<T, ? extends ConsumerProperties, ? extends ProducerProperties>) binder;
 			}
 		};
 	}
-
-	@Bean
-	public MessageCollector messageCollector(BinderFactory binderFactory) {
-		return ((TestSupportBinder) binderFactory.getBinder(null, MessageChannel.class)).messageCollector();
-	}
-
 }

spring-cloud-stream-test-support/src/main/java/org/springframework/cloud/stream/test/binder/TestSupportBinderConfiguration.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 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.stream.test.binder;
+
+import org.springframework.cloud.stream.binder.Binder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.MessageChannel;
+
+/**
+ * Binder {@link org.springframework.context.annotation.Configuration} for the
+ * {@link @TestBinder}.
+ *
+ * Either imported by the {@link TestSupportBinderAutoConfiguration} for the test binder
+ * default usage scenario (superseding all binders on the classpath), or used as a binder
+ * configuration on the classpath when test binder autoconfiguration is disabled.
+ *
+ * @author Marius Bogoevici
+ */
+@Configuration
+public class TestSupportBinderConfiguration {
+
+	private Binder<MessageChannel, ?, ?> messageChannelBinder = new TestSupportBinder();
+
+	@Bean
+	public Binder<MessageChannel, ?, ?> binder() {
+		return messageChannelBinder;
+	}
+
+}

spring-cloud-stream-test-support/src/main/resources/META-INF/spring.binders

@@ -1,2 +1,2 @@
 test:\
-org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration
+org.springframework.cloud.stream.test.binder.TestSupportBinderConfiguration

spring-cloud-stream-test-support/src/main/resources/META-INF/spring.factories

@@ -1,4 +1,5 @@
-org.springframework.boot.autoconfigure.EnableAutoConfiguration:\
-org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration,\
+org.springframework.cloud.stream.test.binder.MessageCollectorAutoConfiguration
 org.springframework.boot.env.EnvironmentPostProcessor=\
   org.springframework.cloud.stream.test.binder.TestBinderEnvironmentPostProcessor

spring-cloud-stream-test-support/src/test/java/org/springframework/cloud/stream/test/aggregate/bean/AggregateWithBeanTest.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.stream.test.aggregate;
+package org.springframework.cloud.stream.test.aggregate.bean;
 
 import java.util.concurrent.TimeUnit;
 

spring-cloud-stream-test-support/src/test/java/org/springframework/cloud/stream/test/aggregate/main/AggregateWithMainTest.java

@@ -14,19 +14,19 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.stream.test.aggregate;
+package org.springframework.cloud.stream.test.aggregate.main;
 
 import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.stream.aggregate.AggregateApplication;
 import org.springframework.cloud.stream.aggregate.AggregateApplicationBuilder;
 import org.springframework.cloud.stream.annotation.EnableBinding;
 import org.springframework.cloud.stream.messaging.Processor;
 import org.springframework.cloud.stream.test.binder.MessageCollector;
-import org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.integration.annotation.Transformer;
@@ -43,9 +43,10 @@ public class AggregateWithMainTest {
 	@Test
 	public void testAggregateApplication() throws InterruptedException {
 		// emulate a main method
-		ConfigurableApplicationContext context = new AggregateApplicationBuilder(
-				TestSupportBinderAutoConfiguration.class).from(UppercaseProcessor.class)
-						.namespace("upper").to(SuffixProcessor.class).namespace("suffix").run();
+		ConfigurableApplicationContext context = new AggregateApplicationBuilder(MainConfiguration.class)
+				.from(UppercaseProcessor.class).namespace("upper")
+				.to(SuffixProcessor.class).namespace("suffix")
+				.run();
 
 		AggregateApplication aggregateAccessor = context.getBean(AggregateApplication.class);
 		MessageCollector messageCollector = context.getBean(MessageCollector.class);
@@ -58,6 +59,10 @@ public class AggregateWithMainTest {
 		context.close();
 	}
 
+	@SpringBootApplication
+	public static class MainConfiguration {
+	}
+
 	@Configuration
 	@EnableBinding(Processor.class)
 	public static class UppercaseProcessor {

spring-cloud-stream-test-support/src/test/java/org/springframework/cloud/stream/test/disable/AutoconfigurationDisabledTest.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 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.stream.test.disable;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.stream.annotation.EnableBinding;
+import org.springframework.cloud.stream.messaging.Processor;
+import org.springframework.cloud.stream.test.binder.MessageCollector;
+import org.springframework.cloud.stream.test.binder.TestSupportBinderAutoConfiguration;
+import org.springframework.integration.annotation.Transformer;
+import org.springframework.integration.support.MessageBuilder;
+import org.springframework.messaging.Message;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Marius Bogoevici
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringBootTest(classes = AutoconfigurationDisabledTest.MyProcessor.class, properties = {
+		"server.port=-1",
+		"spring.cloud.stream.defaultBinder=test"
+})
+@DirtiesContext
+public class AutoconfigurationDisabledTest {
+
+	@Autowired
+	public MessageCollector messageCollector;
+
+	@Autowired
+	public Processor processor;
+
+	@Test
+	public void testAutoconfigurationDisabled() throws Exception {
+		processor.input().send(MessageBuilder.withPayload("Hello").build());
+		// Since the interaction is synchronous, the result should be immediate
+		Message<?> response = messageCollector.forChannel(processor.output()).poll(1000, TimeUnit.MILLISECONDS);
+		assertThat(response).isNotNull();
+		assertThat(response.getPayload()).isEqualTo("Hello world");
+	}
+
+	@SpringBootApplication(exclude = TestSupportBinderAutoConfiguration.class)
+	@EnableBinding(Processor.class)
+	public static class MyProcessor {
+
+		@Transformer(inputChannel = Processor.INPUT, outputChannel = Processor.OUTPUT)
+		public String transform(String in) {
+			return in + " world";
+		}
+	}
+}