#7: Support for in-process transport for testing

samples/grpc-server/src/test/java/org/springframework/grpc/sample/InProcessApplicationContextInitializerTests.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2024-2024 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
+ *
+ *      https://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.grpc.sample;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.grpc.ManagedChannel;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ConfigurableApplicationContext;
+
+@SpringBootTest
+class InProcessApplicationContextInitializerTests {
+
+	@Nested
+	@SpringBootTest(properties = { "spring.grpc.server.host=0.0.0.0", "spring.grpc.server.port=0",
+			"spring.grpc.inprocess.enabled=true" })
+	class WithInProcessEnabled {
+
+		@Autowired
+		private ConfigurableApplicationContext context;
+
+		@Test
+		void testInitialize_WithEnabledProperty_ShouldRegisterServerAndChannel() {
+			ManagedChannel channel = context.getBean("grpcInProcessChannel", ManagedChannel.class);
+			assertThat(channel).isNotNull();
+			assertThat(channel.isShutdown()).isFalse();
+		}
+
+	}
+
+	@Nested
+	@SpringBootTest(properties = { "spring.grpc.server.host=0.0.0.0", "spring.grpc.server.port=0",
+			"spring.grpc.inprocess.enabled=false" })
+	class WithInProcessDisabled {
+
+		@Autowired
+		private ConfigurableApplicationContext context;
+
+		@Test
+		void testInitialize_WithDisabledProperty_ShouldNotRegisterServerAndChannel() {
+			assertThat(context.containsBean("grpcInProcessChannel")).isFalse();
+		}
+
+	}
+
+	@Nested
+	@SpringBootTest(properties = { "spring.grpc.server.host=0.0.0.0", "spring.grpc.server.port=0",
+			"spring.grpc.inprocess.enabled=true" })
+	class WithDefaultInProcessEnabled {
+
+		@Autowired
+		private ConfigurableApplicationContext context;
+
+		@Test
+		void testDefaultEnabledProperty_ShouldRegisterServerAndChannel() {
+			ManagedChannel channel = context.getBean("grpcInProcessChannel", ManagedChannel.class);
+			assertThat(channel).isNotNull();
+		}
+
+	}
+
+}

spring-grpc-test/pom.xml

@@ -35,5 +35,9 @@
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-testing</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>io.grpc</groupId>
+			<artifactId>grpc-inprocess</artifactId>
+		</dependency>
 	</dependencies>
 </project>

spring-grpc-test/src/main/java/org/springframework/grpc/test/InProcessApplicationContextInitializer.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2024-2024 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
+ *
+ *      https://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.grpc.test;
+
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
+
+import io.grpc.ManagedChannel;
+import io.grpc.Server;
+import io.grpc.inprocess.InProcessChannelBuilder;
+import io.grpc.inprocess.InProcessServerBuilder;
+
+/**
+ * An {@link ApplicationContextInitializer} that configures and registers an in-process
+ * gRPC {@link Server} and {@link ManagedChannel} within a Spring
+ * {@link ConfigurableApplicationContext}. This initializer is intended for testing
+ * environments, allowing gRPC communication within the same process without network
+ * overhead.
+ *
+ * @author Andrei Lisa
+ */
+public class InProcessApplicationContextInitializer
+		implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+	private static final String PROPERTY_SOURCE_NAME = "spring.grpc.inprocess.enabled";
+
+	private static final String CHANNEL_NAME = "grpcInProcessChannel";
+
+	@Override
+	public void initialize(ConfigurableApplicationContext applicationContext) {
+		String inProcessEnabled = applicationContext.getEnvironment().getProperty(PROPERTY_SOURCE_NAME, "true");
+
+		if ("true".equalsIgnoreCase(inProcessEnabled) && isJarOnClasspath()) {
+			try {
+				String serverName = InProcessServerBuilder.generateName();
+
+				Server grpcServer = InProcessServerBuilder.forName(serverName).directExecutor().build().start();
+
+				ManagedChannel grpcChannel = InProcessChannelBuilder.forName(serverName).directExecutor().build();
+				applicationContext.getBeanFactory().registerSingleton(CHANNEL_NAME, grpcChannel);
+
+				applicationContext.addApplicationListener(new InProcessServerShutdownListener(grpcServer, grpcChannel));
+
+			}
+			catch (Exception e) {
+				throw new RuntimeException("Failed to initialize in-process gRPC server", e);
+			}
+		}
+	}
+
+	private boolean isJarOnClasspath() {
+		try {
+			Class.forName("io.grpc.inprocess.InProcessChannelBuilder");
+			return true;
+		}
+		catch (ClassNotFoundException e) {
+			return false;
+		}
+	}
+
+}

spring-grpc-test/src/main/java/org/springframework/grpc/test/InProcessServerShutdownListener.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2024-2024 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
+ *
+ *      https://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.grpc.test;
+
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ContextClosedEvent;
+
+import io.grpc.ManagedChannel;
+import io.grpc.Server;
+
+/**
+ * Listener that automatically shuts down the in-process gRPC {@link Server} and
+ * {@link ManagedChannel} when the Spring
+ * {@link org.springframework.context.ApplicationContext} is closed. This helps to ensure
+ * proper resource cleanup after the application context is no longer active, avoiding the
+ * need for manual shutdown calls in tests or other classes.
+ *
+ * @author Andrei Lisa
+ */
+final class InProcessServerShutdownListener implements ApplicationListener<ContextClosedEvent> {
+
+	private final Server grpcServer;
+
+	private final ManagedChannel grpcChannel;
+
+	InProcessServerShutdownListener(Server grpcServer, ManagedChannel grpcChannel) {
+		this.grpcServer = grpcServer;
+		this.grpcChannel = grpcChannel;
+	}
+
+	@Override
+	public void onApplicationEvent(ContextClosedEvent event) {
+		if (grpcChannel != null) {
+			grpcChannel.shutdownNow();
+		}
+		if (grpcServer != null) {
+			grpcServer.shutdownNow();
+		}
+	}
+
+}

spring-grpc-test/src/main/resources/META-INF/spring.factories

@@ -1,3 +1,4 @@
 # Application Context Initializers
 org.springframework.context.ApplicationContextInitializer=\
-org.springframework.grpc.test.ServerPortInfoApplicationContextInitializer
+org.springframework.grpc.test.ServerPortInfoApplicationContextInitializer,\
+org.springframework.grpc.test.InProcessApplicationContextInitializer

spring-grpc-test/src/main/resources/additional-spring-configuration-metadata.json

@@ -0,0 +1,9 @@
+{
+  "groups": [],
+  "properties": [
+    {
+      "name": "spring.grpc.inprocess.enabled",
+      "defaultValue": "true"
+    }
+  ]
+}