Stop assuming that Neo4jDataAutConfiguration ran

This commit updates the conditions in Neo4jReactiveDataAutoConfiguration
so that it gracefully backs off if certain beans are not present, rather
than assuming its sibling Neo4jDataAutoConfiguration has run.

Closes gh-44930

Author: snicoll

Diff for: spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jReactiveDataAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -24,6 +24,7 @@
 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;
 import org.springframework.context.annotation.Bean;
 import org.springframework.data.neo4j.core.ReactiveDatabaseSelectionProvider;
 import org.springframework.data.neo4j.core.ReactiveNeo4jClient;
@@ -44,6 +45,7 @@
 @AutoConfiguration(after = Neo4jDataAutoConfiguration.class)
 @ConditionalOnClass({ Driver.class, ReactiveNeo4jTemplate.class, ReactiveTransactionManager.class, Flux.class })
 @ConditionalOnBean(Driver.class)
+@EnableConfigurationProperties(Neo4jDataProperties.class)
 public class Neo4jReactiveDataAutoConfiguration {
 
 	@Bean
@@ -63,6 +65,7 @@ public ReactiveNeo4jClient reactiveNeo4jClient(Driver driver,
 
 	@Bean(ReactiveNeo4jRepositoryConfigurationExtension.DEFAULT_NEO4J_TEMPLATE_BEAN_NAME)
 	@ConditionalOnMissingBean(ReactiveNeo4jOperations.class)
+	@ConditionalOnBean(Neo4jMappingContext.class)
 	public ReactiveNeo4jTemplate reactiveNeo4jTemplate(ReactiveNeo4jClient neo4jClient,
 			Neo4jMappingContext neo4jMappingContext) {
 		return new ReactiveNeo4jTemplate(neo4jClient, neo4jMappingContext);

Diff for: spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/neo4j/Neo4jReactiveDataAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -56,6 +56,14 @@ class Neo4jReactiveDataAutoConfigurationTests {
 		.withConfiguration(AutoConfigurations.of(Neo4jAutoConfiguration.class, Neo4jDataAutoConfiguration.class,
 				Neo4jReactiveDataAutoConfiguration.class));
 
+	@Test
+	void shouldBackOffIfNoMappingContextIsProvided() {
+		new ApplicationContextRunner().withUserConfiguration(MockedDriverConfiguration.class)
+			.withConfiguration(
+					AutoConfigurations.of(Neo4jAutoConfiguration.class, Neo4jReactiveDataAutoConfiguration.class))
+			.run((context) -> assertThat(context).doesNotHaveBean(Neo4jMappingContext.class));
+	}
+
 	@Test
 	void shouldProvideDefaultDatabaseNameProvider() {
 		this.contextRunner.run((context) -> {