Add back in @ConditionalOnBean to auto-config

Also adds auto-configuration tests for server.

spring-grpc-spring-boot-autoconfigure/src/main/java/org/springframework/grpc/autoconfigure/server/GrpcServerAutoConfiguration.java

@@ -22,6 +22,7 @@ import io.grpc.BindableService;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -34,12 +35,16 @@ import org.springframework.grpc.server.lifecycle.GrpcServerLifecycle;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for gRPC server-side components.
+ * <p>
+ * gRPC must be on the classpath and at least one {@link BindableService} bean registered
+ * in the context in order for the auto-configuration to execute.
  *
  * @author David Syer
  * @author Chris Bono
  */
 @AutoConfiguration
 @ConditionalOnClass(BindableService.class)
+@ConditionalOnBean(BindableService.class)
 @EnableConfigurationProperties(GrpcServerProperties.class)
 public class GrpcServerAutoConfiguration {
 

spring-grpc-spring-boot-autoconfigure/src/test/java/org/springframework/grpc/server/GrpcServerAutoConfigurationTests.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2023-2024 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.server;
+
+import java.util.List;
+
+import io.grpc.BindableService;
+import io.grpc.ServerServiceDefinition;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.FilteredClassLoader;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.grpc.autoconfigure.server.GrpcServerAutoConfiguration;
+import org.springframework.grpc.server.lifecycle.GrpcServerLifecycle;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests for {@link GrpcServerAutoConfiguration}.
+ *
+ * @author Chris Bono
+ */
+class GrpcServerAutoConfigurationTests {
+
+	private ApplicationContextRunner validContextRunner() {
+		BindableService service = mock();
+		ServerServiceDefinition serviceDefinition = ServerServiceDefinition.builder("my-service").build();
+		when(service.bindService()).thenReturn(serviceDefinition);
+		return new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(GrpcServerAutoConfiguration.class))
+			.withBean(BindableService.class, () -> service);
+	}
+
+	@Test
+	void whenGrpcNotOnClasspathAutoConfigurationIsSkipped() {
+		this.validContextRunner()
+			.withClassLoader(new FilteredClassLoader(BindableService.class))
+			.run((context) -> assertThat(context).doesNotHaveBean(GrpcServerAutoConfiguration.class));
+	}
+
+	@Test
+	void whenNoBindableServicesRegisteredAutoConfigurationIsSkipped() {
+		new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(GrpcServerAutoConfiguration.class))
+			.run((context) -> assertThat(context).doesNotHaveBean(GrpcServerAutoConfiguration.class));
+	}
+
+	@Test
+	void whenHasUserDefinedServerFactoryDoesNotAutoConfigureBean() {
+		// NOTE: we use noop server lifecycle to avoid startup
+		GrpcServerFactory customServerFactory = mock(GrpcServerFactory.class);
+		this.validContextRunner()
+			.withBean("customServerFactory", GrpcServerFactory.class, () -> customServerFactory)
+			.withBean("noopServerLifecycle", GrpcServerLifecycle.class, Mockito::mock)
+			.run((context) -> assertThat(context).getBean(GrpcServerFactory.class).isSameAs(customServerFactory));
+	}
+
+	@Test
+	void whenHasUserDefinedServerLifecycleDoesNotAutoConfigureBean() {
+		GrpcServerLifecycle customServerLifecycle = mock(GrpcServerLifecycle.class);
+		this.validContextRunner()
+			.withBean("customServerLifecycle", GrpcServerLifecycle.class, () -> customServerLifecycle)
+			.run((context) -> assertThat(context).getBean(GrpcServerLifecycle.class).isSameAs(customServerLifecycle));
+	}
+
+	@Test
+	void serverFactoryAutoConfiguredAsExpected() {
+		// NOTE: we use noop server lifecycle to avoid startup
+		this.validContextRunner()
+			.withBean("noopServerLifecycle", GrpcServerLifecycle.class, Mockito::mock)
+			.withPropertyValues("spring.grpc.server.address=myhost", "spring.grpc.server.port=6160")
+			.run((context) -> assertThat(context).getBean(DefaultGrpcServerFactory.class)
+				.hasFieldOrPropertyWithValue("address", "myhost")
+				.hasFieldOrPropertyWithValue("port", 6160)
+				.hasFieldOrPropertyWithValue("serverConfigurers", List.of()));
+	}
+
+	@Test
+	void serverLifecycleAutoConfiguredAsExpected() {
+		this.validContextRunner()
+			.run((context) -> assertThat(context).getBean(GrpcServerLifecycle.class)
+				.hasFieldOrPropertyWithValue("factory", context.getBean(DefaultGrpcServerFactory.class)));
+	}
+
+}