© Copyright 2019 Pivotal Software, Inc. All rights Reserved. Testing the Spring Framework Stéphane Nicoll - @snicoll

Who am I? ● Software Engineer at Pivotal (Spring Boot, Spring Framework and start.spring.io) ● Involved in open source for 15 years (Apache Maven, Spring Framework) ● snicoll on the Web (Twitter, Github) - snicoll@pivotal.io ● Based in Liège, Belgium (come over, we have waffles)

Who am I? ● Software Engineer at Pivotal (Spring Boot, Spring Framework and start.spring.io) ● Involved in open source for 15 years (Apache Maven, Spring Framework) ● snicoll on the Web (Twitter, Github) - snicoll@pivotal.io ● Based in Liège, Belgium (come over, we have waffles)

Prerequisite “

Prerequisite “They have a good notion of Java and OOP, know how to use IntelliJ, are used to building tools such as Maven and Gradle, and know JUnit 5 very well. Maurício Aniche

Prerequisite “They have a good notion of Java and OOP, know how to use IntelliJ, are used to building tools such as Maven and Gradle, and know JUnit 5 very well. Maurício Aniche

This is what I was doing during my 1st year

This is what I was doing during my 1st year

Once upon a time…

We stored libs in source control

We stored libs in source control

The power of convention over configuration

And we had to configure the infrastructure ourselves ${hibernate.dialect} ${hibernate.hbm2ddl.auto} ${hibernate.show_sql} ${hibernate.format_sql}

And we had to configure the infrastructure ourselves ${hibernate.dialect} ${hibernate.hbm2ddl.auto} ${hibernate.show_sql} ${hibernate.format_sql}

And chose which libraries to use (and their versions!) org.springframework spring-context ${spring.version} org.springframework spring-orm ${spring.version} org.springframework.data spring-data-jpa 1.3.0.RELEASE

And chose which libraries to use (and their versions!) org.hibernate.javax.persistence hibernate-jpa-2.0-api 1.0.1.Final org.hibernate hibernate-entitymanager 4.1.9.Final runtime mysql mysql-connector-java 5.1.6 runtime

And chose which libraries to use (and their versions!) org.hibernate.javax.persistence hibernate-jpa-2.0-api 1.0.1.Final org.hibernate hibernate-entitymanager 4.1.9.Final runtime mysql mysql-connector-java 5.1.6 runtime

The power of convention over configuration

Live Coding Enough with the slides already!

Summary ● Conventions can significantly improve your productivity ● Best practices for teams and the ecosystem at large ● Provide sane defaults when you don’t or shouldn’t care ● Make upgrade and maintenance easier ● …. but shouldn’t get in your way ● Built on top of an API you could use to implement something slightly or totally different ● Can be customised without having you to redefine everything ● Depending on the scope, not everything can be the target of a convention

See you in 15 Break

Why bother testing at all?

Testing to reduce risk Risk None YOLO Tests 0 Lots

Demo CI/CD in action on start.spring.io

Unit Tests

Unit tests should not require any “framework” @Service public class SubmissionService { @Autowired private SubmissionRepository submissions; @Transactional public Submission create(SubmissionRequest request) { Submission submission = new Submission(); ... return this.submissions.save(submission); } }

Unit tests should not require any “framework” @Service public class SubmissionService { private final SubmissionRepository submissions; public SubmissionService(SubmissionRepository submissions) { this.submissions = submissions; } @Transactional public Submission create(SubmissionRequest request) { Submission submission = new Submission(); ... return this.submissions.save(submission); } }

Unit testing a client for an HTTP API class SpringBootMetadataReaderTests { private final RestTemplate restTemplate = new RestTemplate(); private final MockRestServiceServer server = MockRestServiceServer.bindTo( this.restTemplate).build(); @Test void readAvailableVersions() throws IOException { this.server.expect(requestTo("https://spring.io/project_metadata/spring-boot")) .andRespond(withSuccess(new ClassPathResource( "metadata/sagan/spring-boot.json"), MediaType.APPLICATION_JSON)); ... this.server.verify(); } }

Integration Tests

@SpringBootTest

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@JsonTest @WebMvcTest @WebFluxTest @DataJpaTest @JdbcTest @JooqTest @DataMongoTest @DataNeo4jTest @DataRedisTest @DataLdapTest @RestClientTest

Slice test example @RestClientTest(SpringBootMetadataReader.class) class SpringBootMetadataReaderTests { @Autowired private SpringBootMetadataReader springBootMetadataReader; @Autowired private MockRestServiceServer server; @Test void readAvailableVersions() throws IOException { this.server.expect(requestTo("https://spring.io/project_metadata/spring-boot")) .andRespond(withSuccess(new ClassPathResource( "metadata/sagan/spring-boot.json"), MediaType.APPLICATION_JSON)); ... this.server.verify(); } }

Slice test example with @MockBean @WebMvcTest(controllers = CfpController.class) class CfpControllerTest { @Autowired private MockMvc mvc; @MockBean private SubmissionService submissionService; @Test void submitTalk() throws Exception { given(this.submissionService.create(any())).willReturn(new Submission()); this.mvc.perform(post("/submit") .param("title", "Alice in Wonderland") .param("summary", "my abstract")) .andExpect(status().isFound()) .andExpect(header().string(HttpHeaders.LOCATION, "/submit?navSection=submit")); verify(this.submissionService).create(any()); } }

https://www.testcontainers.org

testcontainers example @DisabledWithoutDockerTestcontainers public class ReactiveRestClientAutoConfigurationTests { @Container static ElasticsearchContainer elasticsearch = new ElasticsearchContainer(); private ApplicationContextRunner contextRunner = new ApplicationContextRunner() .withConfiguration(AutoConfigurations.of( ReactiveRestClientAutoConfiguration.class)); @Test void restClientCanQueryElasticsearchNode() { String endpoint = elasticsearch.getContainerIpAddress() + ":" + elasticsearch.getFirstMappedPort(); this.contextRunner.withPropertyValues( "spring.data.elasticsearch.client.reactive.endpoints=" + endpoint) .run((context) -> { ReactiveElasticsearchClient client = context.getBean( ReactiveElasticsearchClient.class); ... }); } }

Testing Spring Boot

ApplicationContextRunner ● Test utility to prepare a mini ApplicationContext suitable for a very precise scenario: ● Specific auto-configuration(s) ● User configuration, if any ● Environment tuning (properties customization) ● System properties handling ● Starts/Stop the context automatically with a ContextConsumer callback ● AssertJ style assert ● hasSingleBean, doesNotHaveBean, hasFailed ● getBean, getBeans, etc

ApplicationContextRunner example @Test void shouldFailWhenNativeTypesAreNotAvailable() { this.contextRunner .run((context) -> { assertThat(context).hasFailed(); assertThat(context.getStartupFailure()) .hasRootCauseInstanceOf( NativeTypesNotAvailableException.class); }); }

ApplicationContextRunner example @Test void shouldFailWhenNativeTypesAreNotAvailable() { this.contextRunner .withConfiguration(AutoConfigurations.of( Neo4jDataAutoConfiguration.class, TransactionAutoConfiguration.class)) .run((context) -> { assertThat(context).hasFailed(); assertThat(context.getStartupFailure()) .hasRootCauseInstanceOf( NativeTypesNotAvailableException.class); }); }

ApplicationContextRunner example @Test void shouldFailWhenNativeTypesAreNotAvailable() { this.contextRunner .withConfiguration(AutoConfigurations.of( Neo4jDataAutoConfiguration.class, TransactionAutoConfiguration.class)) .withPropertyValues( "spring.data.neo4j.uri=bolt://localhost:7687", "spring.data.neo4j.use-native-types:true") .run((context) -> { assertThat(context).hasFailed(); assertThat(context.getStartupFailure()) .hasRootCauseInstanceOf( NativeTypesNotAvailableException.class); }); }

ApplicationContextRunner example @Test void shouldFailWhenNativeTypesAreNotAvailable() { this.contextRunner .withConfiguration(AutoConfigurations.of( Neo4jDataAutoConfiguration.class, TransactionAutoConfiguration.class)) .withPropertyValues( "spring.data.neo4j.uri=bolt://localhost:7687", "spring.data.neo4j.use-native-types:true") .withClassLoader(new FilteredClassLoader( "org.neo4j.ogm.drivers.bolt.types")) .run((context) -> { assertThat(context).hasFailed(); assertThat(context.getStartupFailure()) .hasRootCauseInstanceOf( NativeTypesNotAvailableException.class); }); }

Classpath tuning @RunWith(ModifiedClassPathRunner.class) @ClassPathOverrides("javax.servlet:servlet-api:2.5") public class NoSuchMethodFailureAnalyzerTests { @Test public void noSuchMethodErrorIsAnalyzed() { Throwable failure = createFailure(); assertThat(failure).isNotNull(); FailureAnalysis analysis = new NoSuchMethodFailureAnalyzer() .analyze(failure); assertThat(analysis).isNotNull(); ... } private Throwable createFailure() { ... } }

Links ● https://spring.io/projects/spring-boot ● https://start.spring.io ● https://spring.io/guides ● https://concourse-ci.org/ ● Testing Spring Boot Applications (Andy Wilkinson @ Spring I/O 2019): https:// www.youtube.com/watch?v=5sjFn9BsAds

© Copyright 2019 Pivotal Software, Inc. All rights Reserved. Thank you! @snicoll