This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Data Neo4j 7.4.0!spring-doc.cn

With Spring Boot and @DataNeo4jTest

Spring Boot offers @DataNeo4jTest through org.springframework.boot:spring-boot-starter-test. The latter brings in org.springframework.boot:spring-boot-test-autoconfigure which contains the annotation and the required infrastructure code.spring-doc.cn

Include Spring Boot Starter Test in a Maven build
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>
Include Spring Boot Starter Test in a Gradle build
dependencies {
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

@DataNeo4jTest is a Spring Boot test slice. The test slice provides all the necessary infrastructure for tests using Neo4j: a transaction manager, a client, a template and declared repositories, in their imperative or reactive variants, depending on reactive dependencies present or not. The test slice already includes @ExtendWith(SpringExtension.class) so that it runs automatically with JUnit 5 (JUnit Jupiter).spring-doc.cn

@DataNeo4jTest provides both imperative and reactive infrastructure by default and also adds an implicit @Transactional as well. @Transactional in Spring tests however always means imperative transactional, as declarative transactions needs the return type of a method to decide whether the imperative PlatformTransactionManager or the reactive ReactiveTransactionManager is needed.spring-doc.cn

To assert the correct transactional behaviour for reactive repositories or services, you will need to inject a TransactionalOperator into the test or wrap your domain logic in services that use annotated methods exposing a return type that makes it possible for the infrastructure to select the correct transaction manager.spring-doc.cn

The test slice does not bring in an embedded database or any other connection setting. It is up to you to use an appropriate connection.spring-doc.cn

We recommend one of two options: either use the Neo4j Testcontainers module or the Neo4j test harness. While Testcontainers is a known project with modules for a lot of different services, Neo4j test harness is rather unknown. It is an embedded instance that is especially useful when testing stored procedures as described in Testing your Neo4j-based Java application. The test harness can however be used to test an application as well. As it brings up a database inside the same JVM as your application, performance and timings may not resemble your production setup.spring-doc.cn

For your convenience we provide three possible scenarios, Neo4j test harness 3.5 and 4.x/5.x as well as Testcontainers Neo4j. We provide different examples for 3.5 and 4.x/5.x as the test harness changed between those versions. Also, 4.0 requires JDK 11.spring-doc.cn

@DataNeo4jTest with Neo4j test harness 3.5

You need the following dependencies to run Using Neo4j 3.5 test harness:spring-doc.cn

Neo4j 3.5 test harness dependencies
<dependency>
    <groupId>org.neo4j.test</groupId>
    <artifactId>neo4j-harness</artifactId>
    <version>3.5.33</version>
    <scope>test</scope>
</dependency>

The dependencies for the enterprise version of Neo4j 3.5 are available under the com.neo4j.test:neo4j-harness-enterprise and an appropriate repository configuration.spring-doc.cn

Using Neo4j 3.5 test harness
import static org.assertj.core.api.Assertions.assertThat;

import java.util.Optional;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.neo4j.harness.ServerControls;
import org.neo4j.harness.TestServerBuilders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.data.neo4j.DataNeo4jTest;
import org.springframework.data.neo4j.core.Neo4jClient;
import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;

@DataNeo4jTest
class MovieRepositoryTest {

	private static ServerControls embeddedDatabaseServer;

	@BeforeAll
	static void initializeNeo4j() {

		embeddedDatabaseServer = TestServerBuilders.newInProcessBuilder() (1)
			.newServer();
	}

	@AfterAll
	static void stopNeo4j() {

		embeddedDatabaseServer.close(); (2)
	}

	@DynamicPropertySource  (3)
	static void neo4jProperties(DynamicPropertyRegistry registry) {

		registry.add("spring.neo4j.uri", embeddedDatabaseServer::boltURI);
		registry.add("spring.neo4j.authentication.username", () -> "neo4j");
		registry.add("spring.neo4j.authentication.password", () -> null);
	}

	@Test
	public void findSomethingShouldWork(@Autowired Neo4jClient client) {

		Optional<Long> result = client.query("MATCH (n) RETURN COUNT(n)")
			.fetchAs(Long.class)
			.one();
		assertThat(result).hasValue(0L);
	}
}
1 Entrypoint to create an embedded Neo4j
2 This is a Spring Boot annotation that allows for dynamically registered application properties. We overwrite the corresponding Neo4j settings.
3 Shutdown Neo4j after all tests.

@DataNeo4jTest with Neo4j test harness 4.x/5.x

You need the following dependencies to run Using Neo4j 4.x/5.x test harness:spring-doc.cn

Neo4j 4.x test harness dependencies
<dependency>
    <groupId>org.neo4j.test</groupId>
    <artifactId>neo4j-harness</artifactId>
    <version>4.4.25</version>
    <scope>test</scope>
    <exclusions>
        <exclusion>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-nop</artifactId>
        </exclusion>
    </exclusions>
</dependency>

The dependencies for the enterprise version of Neo4j 4.x/5.x are available under the com.neo4j.test:neo4j-harness-enterprise and an appropriate repository configuration.spring-doc.cn

Using Neo4j 4.x/5.x test harness
import static org.assertj.core.api.Assertions.assertThat;

import java.util.Optional;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.neo4j.harness.Neo4j;
import org.neo4j.harness.Neo4jBuilders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.data.neo4j.DataNeo4jTest;
import org.springframework.data.neo4j.core.Neo4jClient;
import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;

@DataNeo4jTest
class MovieRepositoryTest {

	private static Neo4j embeddedDatabaseServer;

	@BeforeAll
	static void initializeNeo4j() {

		embeddedDatabaseServer = Neo4jBuilders.newInProcessBuilder() (1)
			.withDisabledServer() (2)
			.build();
	}

	@DynamicPropertySource (3)
	static void neo4jProperties(DynamicPropertyRegistry registry) {

		registry.add("spring.neo4j.uri", embeddedDatabaseServer::boltURI);
		registry.add("spring.neo4j.authentication.username", () -> "neo4j");
		registry.add("spring.neo4j.authentication.password", () -> null);
	}

	@AfterAll
	static void stopNeo4j() {

		embeddedDatabaseServer.close(); (4)
	}

	@Test
	public void findSomethingShouldWork(@Autowired Neo4jClient client) {

		Optional<Long> result = client.query("MATCH (n) RETURN COUNT(n)")
			.fetchAs(Long.class)
			.one();
		assertThat(result).hasValue(0L);
	}
}
1 Entrypoint to create an embedded Neo4j
2 Disable the unneeded Neo4j HTTP server
3 This is a Spring Boot annotation that allows for dynamically registered application properties. We overwrite the corresponding Neo4j settings.
4 Shut down Neo4j after all tests.

@DataNeo4jTest with Testcontainers Neo4j

The principal of configuring the connection is of course still the same with Testcontainers as shown in Using Test containers. You need the following dependencies:spring-doc.cn

<dependency>
    <groupId>org.testcontainers</groupId>
    <artifactId>neo4j</artifactId>
    <version>1.17.6</version>
    <scope>test</scope>
</dependency>

And a complete test:spring-doc.cn

Using Test containers
import static org.assertj.core.api.Assertions.assertThat;

import java.util.Optional;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.data.neo4j.DataNeo4jTest;
import org.springframework.data.neo4j.core.Neo4jClient;
import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;
import org.testcontainers.containers.Neo4jContainer;

@DataNeo4jTest
class MovieRepositoryTCTest {

	private static Neo4jContainer<?> neo4jContainer;

	@BeforeAll
	static void initializeNeo4j() {

		neo4jContainer = new Neo4jContainer<>()
			.withAdminPassword("somePassword");
		neo4jContainer.start();
	}

	@AfterAll
	static void stopNeo4j() {

		neo4jContainer.close();
	}

	@DynamicPropertySource
	static void neo4jProperties(DynamicPropertyRegistry registry) {

		registry.add("spring.neo4j.uri", neo4jContainer::getBoltUrl);
		registry.add("spring.neo4j.authentication.username", () -> "neo4j");
		registry.add("spring.neo4j.authentication.password", neo4jContainer::getAdminPassword);
	}

	@Test
	public void findSomethingShouldWork(@Autowired Neo4jClient client) {

		Optional<Long> result = client.query("MATCH (n) RETURN COUNT(n)")
			.fetchAs(Long.class)
			.one();
		assertThat(result).hasValue(0L);
	}
}

Alternatives to a @DynamicPropertySource

There are some scenarios in which the above annotation does not fit your use case. One of those might be that you want to have 100% control over how the driver is initialized. With a test container running, you could do this with a nested, static configuration class like this:spring-doc.cn

@TestConfiguration(proxyBeanMethods = false)
static class TestNeo4jConfig {

    @Bean
    Driver driver() {
        return GraphDatabase.driver(
        		neo4jContainer.getBoltUrl(),
        		AuthTokens.basic("neo4j", neo4jContainer.getAdminPassword())
        );
    }
}

If you want to use the properties but cannot use a @DynamicPropertySource, you would use an initializer:spring-doc.cn

Alternative injection of dynamic properties
@ContextConfiguration(initializers = PriorToBoot226Test.Initializer.class)
@DataNeo4jTest
class PriorToBoot226Test {

    private static Neo4jContainer<?> neo4jContainer;

    @BeforeAll
    static void initializeNeo4j() {

        neo4jContainer = new Neo4jContainer<>()
            .withAdminPassword("somePassword");
        neo4jContainer.start();
    }

    @AfterAll
    static void stopNeo4j() {

        neo4jContainer.close();
    }

    static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
        public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
            TestPropertyValues.of(
                "spring.neo4j.uri=" + neo4jContainer.getBoltUrl(),
                "spring.neo4j.authentication.username=neo4j",
                "spring.neo4j.authentication.password=" + neo4jContainer.getAdminPassword()
            ).applyTo(configurableApplicationContext.getEnvironment());
        }
    }
}