#281 - Add support for auditing.

We now provide auditing support that can be enabled through EnableR2dbcAuditing.

@Configuration
@EnableR2dbcAuditing
class Config {

  @Bean
  public ReactiveAuditorAware<String> myAuditorProvider() {
      return new AuditorAwareImpl();
  }
}

src/test/java/org/springframework/data/r2dbc/config/AuditingUnitTests.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2020 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.data.r2dbc.config;
+
+import static org.assertj.core.api.Assertions.*;
+
+import lombok.Data;
+import reactor.core.publisher.Mono;
+
+import java.time.LocalDateTime;
+
+import org.junit.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.annotation.LastModifiedBy;
+import org.springframework.data.annotation.LastModifiedDate;
+import org.springframework.data.domain.ReactiveAuditorAware;
+import org.springframework.data.mapping.callback.ReactiveEntityCallbacks;
+import org.springframework.data.r2dbc.mapping.R2dbcMappingContext;
+import org.springframework.data.r2dbc.mapping.event.BeforeConvertCallback;
+import org.springframework.data.relational.core.sql.SqlIdentifier;
+
+/**
+ * Unit tests for {@link EnableR2dbcAuditing}
+ *
+ * @author Mark Paluch
+ */
+public class AuditingUnitTests {
+
+	@EnableR2dbcAuditing(auditorAwareRef = "myAuditor")
+	static class AuditingConfiguration {
+
+		@Bean
+		ReactiveAuditorAware<String> myAuditor() {
+			return () -> Mono.just("Walter");
+		}
+
+		@Bean
+		R2dbcMappingContext r2dbcMappingContext() {
+			return new R2dbcMappingContext();
+		}
+	}
+
+	@Test // gh-281
+	public void enablesAuditingAndSetsPropertiesAccordingly() throws Exception {
+
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AuditingConfiguration.class);
+
+		R2dbcMappingContext mappingContext = context.getBean(R2dbcMappingContext.class);
+		mappingContext.getPersistentEntity(Entity.class);
+
+		ReactiveEntityCallbacks callbacks = ReactiveEntityCallbacks.create(context);
+
+		Entity entity = new Entity();
+		entity = callbacks.callback(BeforeConvertCallback.class, entity, SqlIdentifier.unquoted("table")).block();
+
+		assertThat(entity.created).isNotNull();
+		assertThat(entity.modified).isEqualTo(entity.created);
+		assertThat(entity.modifiedBy).isEqualTo("Walter");
+
+		Thread.sleep(10);
+		entity.id = 1L;
+
+		entity = callbacks.callback(BeforeConvertCallback.class, entity, SqlIdentifier.unquoted("table")).block();
+
+		assertThat(entity.created).isNotNull();
+		assertThat(entity.modified).isNotEqualTo(entity.created);
+		context.close();
+	}
+
+	@Data
+	class Entity {
+
+		@Id Long id;
+		@CreatedDate LocalDateTime created;
+		@LastModifiedDate LocalDateTime modified;
+		@LastModifiedBy String modifiedBy;
+
+	}
+}

src/test/java/org/springframework/data/r2dbc/config/R2dbcAuditingRegistrarUnitTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2020 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.data.r2dbc.config;
+
+import static org.assertj.core.api.Assertions.*;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * Unit tests for {@link R2dbcAuditingRegistrar}.
+ *
+ * @author Mark Paluch
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class R2dbcAuditingRegistrarUnitTests {
+
+	private R2dbcAuditingRegistrar registrar = new R2dbcAuditingRegistrar();
+
+	@Mock AnnotationMetadata metadata;
+	@Mock BeanDefinitionRegistry registry;
+
+	@Test // gh-281
+	public void rejectsNullAnnotationMetadata() {
+		assertThatIllegalArgumentException().isThrownBy(() -> registrar.registerBeanDefinitions(null, registry));
+	}
+
+	@Test // gh-281
+	public void rejectsNullBeanDefinitionRegistry() {
+		assertThatIllegalArgumentException().isThrownBy(() -> registrar.registerBeanDefinitions(metadata, null));
+	}
+}