Spring Boot 2.3 - Spring Data R2dbc - @DataR2dbcTest test slice

CustomerRepositoryTest.java

package com.example.r2dbc;

import io.r2dbc.spi.ConnectionFactory;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.data.r2dbc.DataR2dbcTest;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.data.r2dbc.connectionfactory.init.ResourceDatabasePopulator;
import org.springframework.data.r2dbc.core.DatabaseClient;
import reactor.core.publisher.Flux;
import reactor.test.StepVerifier;

import static org.assertj.core.api.Assertions.assertThat;

@DataR2dbcTest
class CustomerRepositoryTest {

  @Autowired
  private DatabaseClient databaseClient;

  @Autowired
  private CustomerRepository customerRepository;

  /**
   * If you are using R2DBC, the regular DataSource auto-configuration backs off so
   * no schema.sql and data.sql will be loaded automatically!
   *
   * Using Spring Data R2DBC you can initialize the database on startup yourself.
   * In this case we initialize the database in this test.
   *
   * For more info check the docs:
   * https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-initialize-a-database-using-r2dbc
   */
  @Autowired
  public void initializeDatabase(ConnectionFactory connectionFactory) {
    ResourceLoader resourceLoader = new DefaultResourceLoader();
    Resource[] scripts = new Resource[]{
      resourceLoader.getResource("classpath:schema.sql"),
      resourceLoader.getResource("classpath:data.sql")
    };
    new ResourceDatabasePopulator(scripts).execute(connectionFactory).block();
  }

  @Test
  public void testFindByLastName() {
    Customer customer = new Customer("Tim", "van", "Baarsen");
    databaseClient.insert()
      .into(Customer.class)
      .using(customer)
      .then()
      .as(StepVerifier::create)
      .verifyComplete();

    Flux<Customer> findByLastName = customerRepository.findByLastName(customer.getLastName());

    findByLastName.as(StepVerifier::create)
      .assertNext(actual -> {
        assertThat(actual.getFirstName()).isEqualTo("Tim");
        assertThat(actual.getMiddleName()).isEqualTo("van");
        assertThat(actual.getLastName()).isEqualTo("Baarsen");
      })
      .verifyComplete();
  }
}