GCP Datastore : Integration Testing using Spring Boot

In this article, I'll show you how you can create an in-memory datastore used by your tests.

Configuring a Datastore Profile Testing

Spring 3.1 introduced the bean definition profiles which can help us implementing an appropriate configuration for testing datastore staff. So, we'll have a specific profile for the GCP Datastore environment.

	package com.vedrax.company.config;
	import com.vedrax.tester.ITester;
	import com.vedrax.tester.impl.GCPDatastoreTester;
	import org.springframework.context.annotation.Bean;
	import org.springframework.context.annotation.ComponentScan;
	import org.springframework.context.annotation.Configuration;
	import org.springframework.context.annotation.Profile;
	/**
	*
	* @author remypenchenat
	*/
	@Configuration
	@ComponentScan(basePackages = {"com.vedrax"})
	@Profile("datastoreTest")
	public class ServiceTestConfig {
	@Bean(name = "datastoreTester")
	public ITester datastoreTester() {
	ITester tester = new GCPDatastoreTester();
	return tester;
	}
	}

view raw datastore_spring_test_profile hosted with ❤ by GitHub

Basically, the GCPDatastoreTester() class helps us saving data to the local in-memory datastore.

Custom Annotation

In order to support the population of test data for each test case, we will create an annotation in which you can add the JSON file name as argument. In the test execution listener, we'll check for the existence of the annotation and load the data accordingly.

	package com.vedrax.tester;
	import java.lang.annotation.ElementType;
	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import java.lang.annotation.Target;
	/**
	*
	* @author remypenchenat
	*/
	@Retention(RetentionPolicy.RUNTIME)
	@Target(ElementType.METHOD)
	public @interface DataSets {
	String json() default "";
	}

view raw dataset_annotation_java hosted with ❤ by GitHub

We'll use the annotation as follow :

	@DataSets(json = "myTestingDataSet.json")
	@Test
	public void testCreateCompany() {
	//something to test
	}

view raw dataset_annotation_java_test hosted with ❤ by GitHub

Implementing Custom TestExecutionListener

The TestExecutionListener interface in the spring-test module defines a listener API for intercepting the events of the test case execution. 

Process :

1. We check for the existence of the annotation 
2. we will create an instance of LocalServiceTestHelper with LocalDatastoreServiceTestConfig which handles all the GCP environment setup before testing. 
3. Load and insert data using the setDataset() method.

	package com.vedrax.company.config;
	import com.vedrax.tester.DataSets;
	import com.google.appengine.tools.development.testing.LocalDatastoreServiceTestConfig;
	import com.google.appengine.tools.development.testing.LocalServiceTestHelper;
	import org.springframework.test.context.TestContext;
	import org.springframework.test.context.TestExecutionListener;
	import com.vedrax.tester.ITester;
	/**
	*
	* @author remypenchenat
	*/
	public class ServiceTestExecutionListener implements TestExecutionListener {
	private final LocalServiceTestHelper helper
	= new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig());
	private ITester datastoreTester;
	@Override
	public void afterTestMethod(TestContext testCtx) throws Exception {
	helper.tearDown();
	}
	@Override
	public void beforeTestMethod(TestContext testCtx) throws Exception {
	DataSets datasetAnnotation = testCtx.getTestMethod().getAnnotation(DataSets.class);
	helper.setUp();
	if (datasetAnnotation == null) {
	return;
	}
	String datasetName = datasetAnnotation.json();
	if (!datasetName.equals("")) {
	//see configuration file for the bean
	datastoreTester = (ITester) testCtx.getApplicationContext().getBean("datastoreTester");
	datastoreTester.setDataSet(datasetName);
	}
	}
	}

view raw service_test_listener_spring hosted with ❤ by GitHub

As you can see above we override only the beforeTestMethod() and afterTestMethod() in which we call also the setUp() and tearDown() methods.

How To Use

	package com.vedrax.company.service;
	import com.vedrax.company.config.ServiceTestConfig;
	import com.vedrax.company.config.ServiceTestExecutionListener;
	import com.vedrax.company.domain.Company;
	import com.vedrax.tester.DataSets;
	import java.util.Optional;
	import org.junit.Test;
	import static org.junit.Assert.*;
	import org.junit.runner.RunWith;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.boot.test.context.SpringBootTest;
	import org.springframework.test.context.ActiveProfiles;
	import org.springframework.test.context.TestExecutionListeners;
	import org.springframework.test.context.junit4.SpringRunner;
	import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
	/**
	*
	* @author remypenchenat
	*/
	@RunWith(SpringRunner.class)
	@SpringBootTest(classes = {ServiceTestConfig.class})
	@TestExecutionListeners({ServiceTestExecutionListener.class,
	DependencyInjectionTestExecutionListener.class})
	@ActiveProfiles("datastoreTest")
	public class CompanyServiceTest {
	@Autowired
	private CompanyService companyService;
	@DataSets(json = "companyTest1.json")
	@Test
	public void testCreateCompany() {
	Optional<Company> companyOpt = companyService.getCompanyByDomainName("vedrax.com");
	assertTrue(companyOpt.isPresent());
	}
	}

view raw GCP_TEST_LISTENER hosted with ❤ by GitHub

Because we use our own test execution listener, all default listeners are overridden. In order for the DI to work properly we've also added DependencyInjectionTestExecutionListener.